Systematic revision of the western Atlantic file clams, Lima and Ctenoides (Bivalvia:Limoida:Limidae)

Abstract

Marine file clams of family Limidae d'Orbigny, 1846 (+ Radulidae Adams & Adams), characterised by their often colourful mantle and pallial tentacles and by swimming behaviour, are commonly collected and illustrated bivalves. Based on new material from an extensive Florida Keys biodiversity survey plus museum and literature data, western Atlantic species of Lima Bruguière, 1797 (+ Mantellum Röding; Radula Mörch; Limaria Rafinesque; Austrolima Iredale; Meotolima Oyama) and Ctenoides Mörch, 1853 (+ Divaricolima Rovereto) are revised. Lima includes L. marioni Fischer, 1882 (+ L. lata Smith; lectotype selected), and L. caribaea d'Orbigny, 1842 (lectotype selected), distinguished from eastern Atlantic L. lima (Linné) and other species by shell rib number. Ctenoides includes C. scaber (Born, 1778) (+ Ostrea glacialis Gmelin; L. asperula Lamarck; Limaria asperula Link), C. mitis (Lamarck, 1807) (+ L. tenera Sowerby; L. floridana Olsson & Harbison), C. planulatus (Dall, 1886) (lectotype selected), C. sanctipauli Stuardo, 1982, and C. miamiensis, C. obliquus, and C. vokesi, spp. nov. Species distinctions rely mainly on shell characters, although body colour and ornamentation are confirming in some cases. Diagnostic shell characters at the genus-level are supported by new anatomical characters of the gut and tentacles. Known anatomical data for worldwide Lima and Ctenoides species are summarised within a phylogenetic context.

Full text

© CSIRO 2003 10.1071/IS03007 1445-5226/03/050667
www.publish.csiro.au/journals/is Invertebrate Systematics, 2003, 17, 667–710
CSIRO PUBLISHING
Systematic revision of the western Atlantic file clams,
Lima and Ctenoides (Bivalvia: Limoida:Limidae)
Paula M. MikkelsenA,C and Rüdiger BielerB
ADivision of Invertebrate Zoology, American Museum of Natural History,
Central Park West at 79th Street, New York, 10024-5192, USA.
BDepartment of Zoology, Field Museum of Natural History,
1400 South Lake Shore Drive, Chicago, Illinois 60605-2496, USA.
CTo whom correspondence should be addressed. Email: mikkel@amnh.org
Abstract. Marine file clams of family Limidae d’Orbigny, 1846 (+ Radulidae Adams & Adams), characterised by
their often colourful mantle and pallial tentacles and by swimming behaviour, are commonly collected and
illustrated bivalves. Based on new material from an extensive Florida Keys biodiversity survey plus museum and
literature data, western Atlantic species of Lima Bruguière, 1797 (+ Mantellum Röding; Radula Mörch; Limaria
Rafinesque; Austrolima Iredale; Meotolima Oyama) and Ctenoides Mörch, 1853 (+ Divaricolima Rovereto) are
revised. Lima includes L. marioni Fischer, 1882 (+ L. lata Smith; lectotype selected), and L. caribaea d’Orbigny,
1842 (lectotype selected), distinguished from eastern Atlantic L. lima (Linné) and other species by shell rib number.
Ctenoides includes C. scaber (Born, 1778) (+ Ostrea glacialis Gmelin; L. asperula Lamarck; Limaria asperula
Link), C. mitis (Lamarck, 1807) (+ L. tenera Sowerby; L. floridana Olsson & Harbison), C. planulatus (Dall, 1886)
(lectotype selected), C. sanctipauli Stuardo, 1982, and C. miamiensis, C. obliquus, and C. vokesi, spp. nov. Species
distinctions rely mainly on shell characters, although body colour and ornamentation are confirming in some cases.
Diagnostic shell characters at the genus-level are supported by new anatomical characters of the gut and tentacles.
Known anatomical data for worldwide Lima and Ctenoides species are summarised within a phylogenetic context.
Introduction
Members of the marine bivalve family Limidae, commonly
called file shells, file clams, or flame scallops, are among the
most familiar of marine bivalves, as popular elements of
private and museum shell collections, marine aquaria, scuba
divelogs, and colour-illustrated publications on living
molluscs (e.g. Gordon 1990; Cohen and Cohen 1991;
Hornsby 2000; Humann and DeLoach 2002). One species
(Ctenoides scaber) has been ranked as one of two molluscs
most often seen by non-shelling scuba divers (the other
being the flamingo tongue snail, Cyphoma gibbosum (Linné,
1758); Williams 1992). The characteristics most responsible
for this celebrity are the living animals’ relatively large size,
their often colourful mantle and pallial tentacles, and their
propensity for active swimming when disturbed. This com-
bination has lead to numerous academic papers on behav-
iour, reproductive biology, pigmentation, tentacles, etc., of
the various species (e.g. Baily 1950; Mpitsos 1973; Waller
1976; Lin and Pompa 1977; Lodeiros and Himmelman
1999).
Not surprisingly, this popularity has also led to over-
collecting. Bohnsack et al. (1994) reported annual collec-
tions of more than 50000 ‘Rough Fileclams’ (here meaning
a mixture of Ctenoides scaber and C. mitis) in the Florida
Keys during the period 1990–1992. As a result of such
massive commercial harvesting, two Floridian taxa
(C. scaber and Lima caribaea) are among those few species
for which the State of Florida has imposed daily bag limits
for the aquarium trade (Lyons 1992: 14), although they
apparently remain available in commercial quantities (e.g.
Reef Topia 2002; LiveAquaria.com 2003). Ctenoides scaber
was also one of the most frequently used species in ‘sailor’s
valentines’ handmade in Barbados in the mid-1800s (Fondas
2002), and is now commercially exploited for ornamental
use in northern Venezuela (Lodeiros and Himmelman 1999).
Despite their popularity and protected status, the taxonomy
of these species has remained poorly resolved.
Recent systematics of the family Limidae in the western
Atlantic has commonly followed the numerous compilations
and popular works of R. Tucker Abbott (e.g. 1954, 1962a,
1972, 1974, 1986, 1989; also Warmke and Abbott 1961;
Abbott and Morris 1995) in utilising a single genus, Lima
Bruguière, 1797, variously partioned into subgenera. Mean-
while, scholarly works have consistently considered these

668 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
subtaxa as distinct genera, i.e. Lima s. s., Ctenoides Mörch,
1853, Limaria Link, 1807, etc. Among the latter is José
Stuardo’s (1968) revision of worldwide species of Limidae,
completed as a doctoral dissertation at Harvard University.
Although this work included a wealth of new data (including
examination of type material, gross anatomy, distributional
maps, plus introduction of more than 80 new taxa as
manuscript names), only a small extract from it (Stuardo
1982) was ever published and made nomenclatorically
available. Another underacknowledged work is Harold
Vokes’s (1973) review of the common extant western
Atlantic species discussed in the context of fossils from
Florida’s Miocene Chipola Formation.
Phylogenetically, limids display a series of derived
features among bivalves: the shell hinge teeth are reduced,
the muscle organisation is monomyarian (Yonge 1953), the
foot is rotated by 180º relative to the shell and visceral mass
(Seydel 1909; Gilmour 1990). The animals also have
elaborate defensive tentacles, swimming and nesting behav-
iour, morphologically complicated lips (Merrill and Turner
1963; Gilmour 1974, 1990), as well as simple pallial eyes
(Schreiner 1897; Morton 2000).
The family Limidae is currently placed in its own
superfamily Limoidea and order Limoida (Waller 1978;
Butler 1998). Its position within the pteriomorph bivalves
(including Mytiloida, Arcoida, Pterioidea, Ostreoidea, Pecti-
noida, and others) is poorly resolved by all accounts thus far
presented. Using morphological characters, Waller (1998)
proposed a relatively basal position for Limoida supported
by characters of the foot, tentacles, eyes, lips, and ligament
(Fig. 1). Steiner and Hammer’s (2000) combined morpho-
logical/molecular phylogeny suggested a very different
topology, with Limoida in a more derived position with
Pectinoida (Fig. 2), and a different nested set of characters.
Most recently, Giribet and Wheeler’s (2002) combined
morphological/molecular analysis showed yet another
Figs 1–3. Comparison of recently published phylogenies of extant
p
teriomorph bivalves showing unresolved relationships of Limoida
(comprising single family Limidae) with other groups. 1, Based on
morphological data, after Waller (1978). Lettered nodes (with given
synapomorphies in parentheses) correspond to (1a) Pteriomorphia
(dupli- or multivincular ligament system; flattened rectum; Type III
stomach; connected auricles; aniso- or monomyarian adductor
muscles; pigmented larval eye spots) (1b) unnamed clade (dupli-,
multi- or alivincular ligament system; microciliobranchiate gill cilia;
Type III gill/palp association) (1c) Arcoida (arcoid hinge teeth;
compound photoreceptors; cross-lamellar inner shell microstructure;
shell tubules penetrating to inner periostracum) (1d) Limoida
(reversed foot; complex secretory tentacles; lensless eyes; complex
lips; alivincular ligament), and (1e) unnamed clade (calcitic outer shell
layers with columnar prismatic microstructure). 2, Combined
morphological/molecular data, after Steiner and Hammer (2000).
Letter notes (with given synapomorphies) correspond to (2a)
Pteriomorphia (discontinuous ligament, Type III stomach, flattened
rectum, connected auricles, juvenile branchial eye) (2b) unnamed
clade (Type III gill/palp association, no opisthodetic ligament,
microlaterofrontal cilia) (2c) unnamed clade (calcitic prisms in outer
shell layer, inequivalve, byssal notch, dominant right abdominal sense
organ) (2d) unnamed clade (complex pallial tentacles, Type IV
stomach, cross-lamellar inner shell layer, monomyary) (2e) unnamed
clade (pallial eyes) (2f) unnamed clade (cemented right valve).
3, Combined morphological/molecular data, after Giribet and Wheeler
(2002). Letter notes (with given synapomorphies) correspond to (3a)
Pteriomorphia (egg cleavage with polar lobe formation) (3b) unnamed
clade (Type III gill/palp association, byssal gape, microlaterofrontal
cilia); (no synapomorphies discussed for more distal clades).

Western Atlantic Limidae Invertebrate Systematics 669
arrangement in their preferred tree (i.e. Limoida in sister-
group relationship with Anomioidea; Fig. 3) although clade
support was weak and the relationships between Limoida
and most other pteriomorphs were acknowledged as
unstable. The strength of all of these analyses relative to
Limoida/Limidae can be debated because none has incor-
porated more than a few representative limid species. More
relevant to this topic, a phylogenetic hypothesis for Limidae
and its component genera has not yet been presented.
Nevertheless, these higher-level studies indicate the rele-
vance of anatomical characters to phylogenetic studies
within Pteriomorphia.
The goal of this study was to revise the western Atlantic
species of two large-bodied limid genera, Lima s. s. and
Ctenoides, from newly collected material from the Florida
Keys, supplemented by museum collections and literature
data; an earlier version was presented in poster format
(Mikkelsen and Bieler 1998). During subsequent research
on additional museum holdings, several undescribed species
and others seldom acknowledged in the western Atlantic
literature were discovered and are also described herein. The
discussion concerns the type species of both nominal
genera, L. lima (Linné, 1758) and C. scaber (Born, 1778),
respectively, and is thus of relevance to higher-level system-
atics in this family. Of special interest was investigation into
anatomical characters to corroborate or refute currently
accepted classification at the species and genus levels, which
might ultimately prove useful in a taxonomically compre-
hensive phylogenetic analysis of Limidae.
Materials and methods
This study is fourth in a series of systematic revisions (following Bieler
and Mikkelsen 1998; Bieler et al. 1998; Mikkelsen and Bieler 2001)
published as part of an ongoing investigation of marine molluscan
biodiversity in peninsular Florida and the Florida Keys (Monroe
County), formally initiated by the authors in 1994. Consecutively
numbered stations comprising collections in the Florida Keys Mollus-
can Diversity Research Project are preceded by an ‘FK’ acronym in the
following text and in an ‘Accessory Publication’ (accompanied by full
locality data) on the Invertebrate Systematics website (http://www.pub-
lish.csiro.au/journals/is). Living animals were collected mainly by
hand during scuba diving on coral reefs and shallow-water (2–10 m)
patch reefs, rubble areas, and ledges; additional empty shells were
taken by ponar grab or otter trawl deployed from various research
vessels. For faunal analyses, this study divided the Florida Keys into
four regions: Upper (Key Largo to Craig Key), Middle (Fiesta Key to
the western end of Seven-Mile Bridge), Lower (Little Duck Key to
Rebecca Shoal, west of the Marquesas), and the Dry Tortugas Archi-
pelago. Although also political divisions, these regions are supported
by hydrological and geological data (summarised by Mikkelsen and
Bieler 2000). Samples from the Upper, Middle and Lower Keys
regions were further categorised as Florida Bay or oceanside, to
facilitate analysis of the environmental tolerance of species to the
lower salinities and greater temperature fluctuations of the shallow
bayside waters. Geographic distributions outside the Florida Keys were
compiled using a fairly exhaustive survey of the literature and museum
collections. Sources of these data, as well as additional synonymy
entries, are available in an ‘Accessory Publication’ on the Invertebrate
Systematics website (http://www.publish.csiro.au/journals/is).
Living animals (Figs 43–45) were photographed in an aquarium
with a 35-mm single-lens reflex camera. For anatomical observation,
specimens were relaxed by chilling in a household refrigerator assisted
by the addition of magnesium sulfate crystals (Epsom salts) to their
seawater supply, or in an isotonic aqueous magnesium chloride solu-
tion. Features of live-dissected specimens (Figs 46–47) were photo-
graphed with a 35-mm single-lens reflex camera through a phototube
on an Olympus SZH10 stereomicroscope. Voucher specimens were
fixed in 5% formalin, later transferred to 70% ethanol, and deposited in
the American Museum of Natural History (AMNH), New York and the
Field Museum of Natural History (FMNH), Chicago. Frozen tissue
samples are deposited in the Ambrose Monell Collection for Molecular
and Microbial Research at AMNH.
Other cited repositories include:
ANSP Academy of Natural Sciences of Philadelphia
BMNH The Natural History Museum, London [ = British
Museum (Natural History)]
BMSM Bailey-Matthews Shell Museum, Sanibel Island, Florida
DMNH Delaware Museum of Natural History, Wilmington
HBOM Harbor Branch Oceanographic Museum, Harbor Branch
Oceanographic Institution, Ft Pierce, Florida
MCZ Museum of Comparative Zoology, Harvard University,
Cambridge, Massachusetts
MTD Staatliche Naturhistorische Sammlungen Dresden,
Museum für Tierkunde, Germany [ = Museum für
Tierkunde, Dresden]
MZSP Museu de Zoologia, Universidade de São Paulo, Brazil
NCSM North Carolina State Museum of Natural Sciences,
Raleigh
NCSM-IMS NCSM, Institute of Marine Sciences collection
SBMNH Santa Barbara Museum of Natural History, Santa
Barbara, California
UMML Rosenstiel School of Marine and Atmospheric Science,
University of Miami, Florida [ = University of Miami
Marine Laboratory]
USNM National Museum of Natural History, Smithsonian
Institution, Washington, DC [ = United States National
Museum]
Abbreviations used throughout the text are: alc, fluid-preserved
(alcohol) specimen; FK, Florida Keys; juv, juvenile or subadult
specimen; LV, left valve; RV, right valve; unverified, specimens from
that locality not seen as part of this study; V, valve.
Shell measurements (taken with calipers or with an ocular microm-
eter on a stereomicroscope) include: maximum height from umbo to
farthest distal point on free edge; maximum width (=shell length)
perpendicular to axis of height; maximum inflation with valves
articulated and fully closed. Ribs were counted at the growth edge on
the main body of the shell, and are expressed as that per valve
exclusive of the auricles. All measurements and meristics were taken
from the left valve whenever possible. Size is expressed as shell height
unless otherwise noted. Determination of significance between sets of
Ctenoides scaber and C. mitis meristics employed the Mann–Whitney
U-test and Student’s t-distribution (Sokal and Rohlf 1981).
Specimen photography used a variety of equipment and techniques.
Whole-valve and detail light micrography (e.g. Figs 12–14) used a
Microptics® micro/macro imaging system equipped with an ML–1000
fibre-optic lighting package and a high-resolution Nikon® single-lens
reflex digital camera. Valves to illustrate shape variation (Figs 16–19,
23–25) were coated with magnesium oxide to neutralise distracting
periostracal and colour features, then photographed using a single-lens
reflex camera in 4″ × 5″ format. For scanning electron microscopy
(SEM), dried shells were mounted on stubs, coated with gold-

670 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
palladium, and scanned on a Zeiss DSM-950 scanning electron
microscope at AMNH.
Common (vernacular) species names are provided for all taxa.
Those from North American waters correspond to the American
Fisheries Society listing (Turgeon et al. 1998) and are of particular
relevance in this case: the Florida Statute on the recreational harvesting
of restricted marine life species (Section 370.01(20), Rule 68B–42,
also known as ‘Florida Dive and Game Laws’ or ‘Marine Life Rule’)
emphasises common rather than scientific names. (The current word-
ing of Chapter 68B–42 (3)(i) (http://marinefisheries.org/Ch68B-
42.htm, last accessed 09 December 2002), ‘Fileclams – any species of
the Genus Lima,’ reflects the need for updated taxonomy; Florida State
authorities have been notified and changes were underway as of
December 2002.)
As the name-bearing genus, Lima is presented first, with its two
species, L. caribaea and L. marioni, in alphabetical order. Within
Ctenoides, the type species C. scaber is presented first, followed by the
similar C. mitis for ready comparison; the previously named
C. planulatus and C. sanctipauli are next, followed by the three new
species, C. miamiensis, C. obliquus and C. vokesi.
Taxonomic results
Family Limidae d’Orbigny
Limidae d’Orbigny, 1846: 651
Radulidae H. & A. Adams, 1858: 556
The name Limidae is usually credited to Rafinesque, 1815
(e.g. Cox and Hertlein 1969: N385; Coan et al. 2000: 203).
Rafinesque (1815: 147) based his new family-group name
(as subfamily ‘Limaridia’ of family ‘Byssiferia’) on Limaria
Rafinesque, 1815, not on Lima Bruguière, 1797. Rafinesque
thus created a family name Limariidae, not Limidae.
However, Limaria Rafinesque was introduced as an apparent
replacement name for Lima, as ‘[genus no.] 16. Limaria
R[afinesque] Lima’ (1815: 147). By listing the name in this
fashion Rafinesque did not introduce his Limaria as distinct
from Lima, and Limaria is here interpreted as an unjustified
emendation. According to ICZN (1999) Art. 35.4.1, a
‘family-group name based upon an unjustified emendation
… must be corrected.’ The corrected name thus becomes
Limidae Rafinesque, 1815, which is in accordance with
prevailing usage.
The situation is further complicated in that Limaria
Rafinesque is a junior homonym of Limaria Link 1807, the
latter a limid group distinct from Lima. ICZN (1999) Art. 39
specifies that the ‘name of a family-group taxon is invalid if
the name of its type genus is a junior homonym…’ This
creates a conundrum: the previously described correction
under ICZN (1999) Art. 35.4.1. changed the name of the
family, not the identity of its type genus. Limidae Rafin-
esque remains based on the available (but invalid) name
Limaria Rafinesque, and the family name thus is invalid
because Limaria Rafinesque is a junior homonym.
D’Orbigny’s ‘Voyage dans l’Amérique méridionale’
(1846: 651–652) appears to be the earliest work to employ
the family name, as ‘Famille des Limidae, d’Orbigny,’
stating ‘Nous ne classons dans cette famille que le seul
genre Lima.’
Genus Lima Bruguière
Lima Bruguière, 1797: pl. 206.
Radula Klein, 1753: 135 [pre-Linnean].
Mantellum Röding, 1798: 160 [non Mantellum ‘Bolten’ sensu
Mörch 1853: 57 = Limaria Link, 1807].
Radula ‘Klein’ Mörch, 1853: 57.
Limigenus Renier, 1807: pl. 7 [unavailable; ICZN 1956c: Opinion
427].
Limaria Rafinesque, 1815: 147 [a replacement name for Lima; not
of Link, 1807].
Glaucion Oken, 1815: ix [unavailable; ICZN 1956a: Opinion 417].
Austrolima Iredale, 1929: 165.
Meotolima Oyama, 1943: 36.
Type species
‘La lime ordinaire’ Lima alba Cuvier, 1797 [ = Ostrea lima
Linné, 1758; see also discussion by Cox and Hertlein 1969:
N385–386], by subsequent monotypy (Cuvier 1797: 421).
The type species of Mantellum Röding is Ostrea lima Linné,
1758, by subsequent designation (Gray 1847: 200). The type
species of Radula Mörch is Limaria vulgaris Link, 1807, by
tautonomy. The type species of Austrolima Iredale is Lima
nimbifer Iredale, 1924, by original designation. The type
species of Meotolima Oyama is Lima (Meotolima)
ogasawarana Oyama, 1943 [non Lima ogasawaraensis
Habe, 1993], by monotypy.
Diagnosis
Shell whitish, inequilateral, with strongly demarcated,
oblique anterodorsal ridge, only very narrowly gaping
anteriorly (byssal gape); posterior margin not gaping. Sculp-
ture of non-divaricating, solid, radial ribs; scales coarse,
terminally blunt, somewhat curved around hollowed under-
side (‘fingernail-like’), arising from smooth rib surface
(Fig. 6). Hinge line narrow, obliquely skewed postero-
laterally. Inner margin strongly crenulated, reflecting
exterior ribs. Periostracum non-persistent. Animal with rows
of relatively short, more-or-less cylindrical, ungrooved, non-
annulated pallial tentacles. Small visceral mass containing
closed intestinal loop.
Remarks
The name Lima is usually credited to Bruguière but the
authorship of the plate introducing Lima in Bruguière’s
Tableu was also attributed to Lamarck (Coan et al. 2000:
597). We follow the latest available critical compilation, by
Evenhuis and Petit (2003), which attributed this plate to
Bruguière. Lima was introduced as a bare generic name,
accompanied by illustrations of six species.
The Nomenclator Animalium (Hesse 1940: 2995) credits
Bruguière (1792) for having introduced the genus name
Radula. Bruguière (1792: 537) reviewed Klein’s classifi-

Western Atlantic Limidae Invertebrate Systematics 671
cation, but did not use Radula as the valid name of a taxon;
the name is thus not available under ICZN (1999) Art.
11.5.2. The same is true for Deshayes’ (1832: 876) mention
of Radula ‘Klein’ as a ‘rather exact’ synonym of Lima, who
considered the name ‘inadmissible’ because Klein included
species that were foreign to him. The earliest available use of
Klein’s Radula appears to date from Mörch (1853). Mörch
originally included three species (R. caribea, R. vulgaris,
R. squamosa [with Ostrea lima in its synonymy]), as well as
a tentatively introduced new form ‘var.? interlirata.’ The
type species, by tautonomy, is Limaria vulgaris Link, 1807,
which had ‘Radula Ch[emnitz]’ in its original synonymy.
Stuardo’s (1968: 66) acceptance of Ostrea lima Linné, 1758,
as a subsequent type designation (referring to Winckworth
1930: 116) is in error, as that species was not originally
included by Mörch. Radula Mörch is preoccupied by
Radula Gray, 1842, a nominal genus he tentatively placed in
the gastropod family Naticidae. Gray’s earlier mention of
this name, as ‘Radula ?’ in the family Naticidae (1840: 151)
is a nomen nudum. Gray (1847: 150), tentatively moving the
genus to Neritopsidae, added ‘Nerita granulata’ as type by
subsequent monotypy.
The following section covers all western Atlantic species
of Lima s.s., e.g. L. caribaea and L. marioni. Other nominal
western Atlantic Lima species listed in frequently used
checklists and field guides (e.g. Abbott 1974; Turgeon et al.
1998) are now regularly referred to other genera as part of
the general (morphologically supported) trend of elevating
limid subgenera to genus-level (see also Stuardo 1968).
Therefore Lima pellucida C. B. Adams, 1846, and L. locklini
McGinty, 1955, are now referred to Limaria Link, 1807;
Lima bullisi Vokes, 1963, and L. excavata (Fabricius, 1779)
are now in Acesta H. & A. Adams, 1851; and Lima albicoma
Dall, 1886, is now in Divarilima Powell, 1958. Lima
floridana Olsson & Harbison, 1953, L. tenera Sowerby,
1843, and L. scabra (Born, 1778) are now species (or junior
synonyms) of Ctenoides (see below).
Lima caribaea d’Orbigny
Spiny file clam
(Figs 4–7, 43)
Lima caribaea d’Orbigny, 1842: pl. 28, figs 17–19 (fig. 5). –
d’Orbigny 1846: 354; d’Orbigny 1853: 337; d’Orbigny 1855: pl.
28, figs 17–19 (see remarks on the dates of d’Orbigny’s
‘SAGRA Report’ below); Pulley 1952: 99, pl. 7, fig. 5; Sander
and Lalli 1982: table 4; Odé 1988: 18; Espinosa et al. 1994: 115;
Mikkelsen and Bieler 1998: 223; Mikkelsen and Bieler 2000:
74; Redfern 2001: 207, pl. 85, fig. 850; INBio 2001; Espinosa
and Ortea 2001: 66.
Radula (Radula) caribaea. – Mörch 1853: 57.
Radula caribaea. – H. and A. Adams 1858: 557.
Lima (Lima) cf. caribaea. – Vokes 1973: 88–89, pl. 1, fig. 1.
Lima (Lima) caribaea. – Vokes and Vokes 1984: 38, pl. 37, fig. 3.
Lima carribea [sic]. – Cockerell 1894: 113.
Lima lima (non Ostrea lima Linné, 1758). – Dall 1898: 767; Dall
and Simpson 1901: 468; Maury 1920: 63; Peile 1926: 93;
Johnson 1934: 26; Webb 1945: 29, pl. 12, fig. 2; Smith 1940: 97,
text-fig. 1315; Smith 1945: 36, pl. 10, fig. 5; Abbott 1954: 370,
fig. 35 g; Rice and Kornicker 1962: 381, pl. 8, figs 8a–8b; Abbott
1968: 212–213, text-fig. 5; Kennedy 1969: 7; Nordsieck 1969:
58, pl. 9, fig. 36.20 (in part); Abbott 1970: 147, pl. 11, fig. 285;
Magnotte 1970–1979: 74, text-fig. 5; Stanley 1970: 143–144, pl.
13, figs 9–14; Morris 1973: 32–33, pl. 18, fig. 5; Abbott 1974:
453, pl. 20, fig. 5240; Dance 1974: 239; Emerson and Jacobson
1976: 374–375, pl. 39, fig. 21; Eisenberg 1981: 164, text-fig. 1;
Rehder 1981: 696; Abbott 1984: 51, text-fig. 5 (upper photo);
Abbott 1986: 212, fig. 5; Jensen and Harasewych 1986: 472,
text-fig. 157; Oliver 1987: 1; Turgeon et al. 1998: 27; Williams
1988: 86, fig. (bottom); Lipe and Abbott 1991: 72, text-fig. 5
(upper photo); Humann 1992: 248–249, text-fig.; Lawson 1993:
47, text-fig; Poppe and Goto 1993: 76 (in part); Diaz Merlano
and Puyana Hegedus 1994: 62, pl. 10, fig. 95; Lyons and Quinn
1995: J–10; Goto and Poppe 1996: 1: 451, 2: 897,
‘cosmopolitan’; Williams and Carmichael 1997: 86, fig.;
Pointier and Lamy 1998: 188, text-fig.; Humann and DeLoach
2002: 326–327, text-fig.; INBio 2001.
Lima (Lima) lima (non Ostrea lima Linné, 1758). – Jaume 1946: 99;
McLean 1951: 34, pl. 7, fig. 3; Warmke and Abbott 1961: 171,
fig. 34f; Humfrey 1975: 230, pl. 27, fig. 9; Lindner 1977: 234,
pl. 56, fig. 6 (in part); Odé 1979: 26; Hemmen and Hemmen
1979: 165; Andrews 1981: 99; Andrews 1994: 107–108, text-
fig., colour plate C–17; Rios 1994: 243, pl. 84, fig. 1188.
Lima lima caribaea. – Jaume and Pérez Farfante 1942: 39
[Pleistocene]; Abbott and Morris 1995: 32 (as L. lima), pl. 26,
fig. 10; Goto and Poppe 1996: 1: 451, 2: 897 (Caribbean).
Lima squamosa (misidentification; non Lima squamosa Lamarck,
1801). – Wheatley 1842: 15; Wheatley 1845: 16; Schramm
1869: 23; Simpson 1887–1889: 70; Lamarck 1819: 156 (mers
d’Amérique); Beau in Petit de la Saussaye 1853: 416; Tryon
1873–1874: 197, pl. 44, fig. 544; Dall 1886: 224; Dall 1896: 18.
Lima multicostata (misidentification; non Lima multicostata
Sowerby, 1843). – Smith 1885: 288–289 (in part); Peile 1926:
93.
Lima (Lima) lima forma multicostata (misidentification; non Lima
multicostata Sowerby, 1843). – Aguayo and Jaume 1948: 1.
Lima tenera (misidentification; non Lima tenera Sowerby, 1843). –
Webb 1935: 64, text-fig.
Additional non-essential synonomies are provided as Accessory
Material on the Invertebrate Systematics website.
Material examined
Type material. 1 pair, 1 RV, 4 LV, Cuba (BMNH 1854.10.4.609,
14.5–25.1 mm, 26–32 ribs, vidi); largest specimen and figured LV
(25.1 mm, 27 ribs; d’Orbigny 1842: fig. 17), here designated as lecto-
type. D’Orbigny (1842, 1846) originally described Lima caribaea from
the SAGRA Expedition materials (publication dates for the French and
Spanish editions of this work have never been rigorously compiled and
cited dates for the many new western Atlantic taxa vary substantially;
most sources (Dall 1885; Aguayo 1943, citing earlier authors; Petit and
Harasewych 1990; Coan et al. 2000) consider 1840–1853 for the two-
volume French text and 1842 for the 28 plates accompanying the
French edition (including L. caribaea), followed by 1845–1846 for the
Spanish text and 1855 for the 28 plates (unchanged from the French
edition, but with a Spanish title page; dated here from the cover page of
the AMNH Library copy)); the type locality is Cuba, by original desig-
nation. Palmer (1947: 103) quoted Carpenter’s notes on this BMNH
type material (d’Orbigny’s no. 541; 1842: pl. 28, figs 17–19) in

672 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
1863–1864, as ‘the ribbed one called squamosa’, referring to
Lamarck’s (1819) misidentification.
Selected other material examined.Bermuda: 1 pair, Challenger
Bank (AMNH 158315); 1 pair, Hamilton Island (FMNH 29920); 3 juv
V, North Rock (FMNH 293003); 2 pair (live-collected), near Charles
Island (FMNH 30323); 20 pair (DMHH 202545). North Carolina: 1 V,
off Wilmington (USNM 811262). South Carolina: 1 pair, Charleston
(AMNH 91127). Florida: 1 pair (DMNH 7656; figured by Abbott
1974: pl. 20, fig. 5240); 1 alc, off St Lucie County (HBOM 064:01045);
1 pair, Lake Worth (BMSM 224); 1 V, Boca Raton (AMNH 120545);
4 pair (live-collected), Pompano Beach (HMNS 13683); 1 alc, off
Miami (UMML 30.11914); 1 pair, Cape Florida (AMNH 71388);
7 pair, 3 pair (live-collected), Biscayne Bay (AMNH 292005); 2 pair
(live-collected), Biscayne Bay (AMNH 210144); 1 pair, Soldier Key
(FMNH 189919); 1 pair (live-collected), Key Largo (HMNS 10487);
1 V, Key Largo, Angelfish Ck (FK–204; FMNH 301248); 1 alc, 3 V,
Molasses Reef (FK–202; AMNH 299640, FMNH 296729); 1 pair,
Upper Matecumbe Key (AMNH 247511); 1 pair, Grassy Key (AMNH
86993); 3 pair (live-collected), Key Vaca (AMNH 247510); 1 alc,
2 pair, 6 V, East Washerwoman Shoal (FK–115; AMNH 299636,
FMNH 301244); 1 alc, 6 V, Marathon, Key Vaca (FK–121; AMNH
299639/232684); 2 pair, Pigeon Key (DMNH 86542); 66 pair, Missouri
Key (FMNH 182935; Fig. 4); 1 pair, Ohio Key (AMNH 247512);
3 pair, Bahia Honda Key (AMNH 121127); 5 alc, Ramrod Key
(FK–047; AMNH 299635); 4 pair (live-collected), Looe Key (AMNH
243071); 2 pair, Key West (DMNH 86551); 10+ V, Key West (CMNH
61.2720); 2 pair, Dry Tortugas (UMML 28.1615); 1 alc, Dry Tortugas
(HBOM 064:01230); 10 pair, 1 V, Dry Tortugas (USNM 107509); 1 alc,
2 V, Dry Tortugas, Garden Key (FK–089; AMNH 232678); 4 pair,
Sanibel Island (FMNH 208463); 1 pair, Sanibel Island (UMML
28.821); 3 juv pair (live-collected), off Cape San Blas (HMNS 37138).
Texas: 3 V, Galveston (FMNH 16070); 1 V, off Corpus Christi (HMNS
5707); Mexico: 4 pair, Quintana Roo (DMNH 125099). Belize: 5 pair,
Carrie Bow Cay (USNM 771136). Honduras: 2 pair (USNM 811221);
1 juv alc, Cabo Gracias a Dios (UMML 30.11931). Nicaragua: 1 pair,
Isla de Providencia (UMML 30.11955). Panama: 1 RV, Canal Zone
(UMML); 1 pair (live-collected), Bocas del Toro (Lloyd Collection).
Bahamas: 1 LV, Cay Sal Bank (UMML 30.11940); 6 pair, Nassau
(FMNH 82274); 1 pair, New Providence (AMNH 210142); 3 juv pair
(live-collected), Bimini (AMNH 91364); 1 pair, Exuma (AMNH
266430); 1 alc, 1 pair, Andros (AMNH 307192/307193); 2 alc, Andros
(AMNH 307191). Turks and Caicos Islands: 1 pair, Providenciales
(HMNS 21285); 3 alc, 5 pair, 5 V, 1 fragment (UMML 30.11932).
Cuba: 1 pair, Oriente Province (USNM 487740); 1 alc, off W coast
(UMML 30.11915); 1 pair, Havanna (MTD 26568; K. Schniebs, per-
sonal communication). Cayman Islands: 3 pair, Grand Cayman Island
(ANSP 199473). Jamaica: 2 V, Montego Bay (USNM 458144); 1 alc,
2 juv alc (UMML 30.11926). Hispaniola: 17 pair (live-collected), 2 V,
Dominican Republic (AMNH 94654); 1 juv alc, S of Hispaniola
(UMML 30.11930). Puerto Rico: 4 pair (live-collected), off Cano
Gordo (AMNH 665). Virgin Islands: 1 pair (including largest recorded
specimen), St Thomas (USNM 406980); 1 V, Mosquito Island (FMNH
197345); 1 V, Nevis (S. Hewitt Collection); 1 alc, 2 juv alc (UMML
30.11924). Antigua: 7 alc, 1 pair (UMML 30.11960). Guadeloupe:
2 pair, Grand Terre Island (ANSP 281041). Martinique: 1 alc, 3 juv
alc, 4 pair, Bourg de Case Pilote (UMML 30.11842). St Vincent: 2 juv
alc (UMML 30.11923). Grenadines: 1 V, Palm Island (AMNH
148661). Barbados: 1 pair, off Lord’s Castle (USNM 216956).
Grenada: 6 alc, 11 juv alc, 1 LV, 1 juv pair (UMML 30.11922). Tobago
Island: 5 V (AMNH 85359). Colombia: 1 pair (live-collected), Carta-
gena (FMNH 78678); 1 LV juv, Old Providence Island (AMNH
307295). Netherlands Antilles: 3 pair (live-collected), Bonaire
(AMNH 247515); 1 V, Curaçao (AMNH 114045); 1 alc (UMML
30.11918). Brazil: 1 pair, São Sebastiao de Vicosa (USNM 767412).
Diagnosis
Shell white, heavy, with 22–34 scaly radial ribs and smooth
interspaces. Prodissoconch 195 µm. Animal with multiple
rows of short pallial tentacles; soft body white with varying
degrees of orange to purplish-red markings.
Description
Shell whitish, 20–30 mm (range 3–56.1 mm, mean 25.5 ±
10.6 mm s.d., n = 61; previously recorded maxima 55 mm
by Dall and Simpson (1901) and Emerson and Jacobson
(1976) and 42.5 mm by Vokes (1973), relatively thick-
shelled, equivalve, inequilateral, roughly triangular in out-
line (Figs 4–5). Compressed laterally, very narrowly gaping
anteriorly (byssal gape); posterior margin not gaping. Exter-
nal shell surface sculptured with 22–34 scaly radial ribs
(mean 27.2 ± 2.3 s.d., n = 292), not divaricating; interspaces
smooth with only faint growth lines (Fig. 6). Posterior
auricle extending as is typical for Limidae species, anterior
auricle ‘hidden’ from dorsal view below strongly demar-
cated, oblique anterodorsal ridge (called the ‘lunular border’
by Stuardo 1982) adorned with 5–8 finer radial ribs.
Umbones central, small, extending as minute points above
the hinge line. Prodissoconch smooth, D-shaped, 195 µm in
maximum length (AMNH, n = 1), bounded from teleoconch
by distinct double growth line (Fig. 7). Hinge line narrow,
obliquely skewed posterolaterally, with a shallow, central,
triangular resilifer. Hinge teeth consisting of small elon-
gated tubercles at lateral ends of hinge line in left valve,
articulating with shallow elongated depressions at lateral
ends of hinge line in right valve; anterior tubercle (at dorsal
end of flaring byssal gape) somewhat larger. Inner margin
crenulated, reflecting exterior ribs. Pallial line simple, entire.
Monomyarian; adductor muscle scar posterior, with slightly
smaller pedal retractor muscle scar ventral and slightly
medial to it; pedal protractor muscle scar tiny, central and
just below umbo. Periostracum non-persistent.
Shell gaping ~10° in living individuals at rest. Animal
(Fig. 39) with multiple rows of relatively short, papillose
(but non-annulated) pallial tentacles; darkly pigmented eyes
(13 per side in 12.4-mm specimen, FK–121) evenly dis-
persed at mantle edge between tentacle bases. Extensive
pallial veil (=curtain) smooth, extending from mantle edge,
inside tentacle rows, to fully span opening of normally
gaping shell when alive. Tentacles, veil and mantle white
and usually mottled in living individuals with orange to
reddish purple to varying extent (Fig. 43). Foot relatively
large, pigmented reddish purple in living individuals, with
transversely ridged, unpigmented ‘sole’ at tip (as in
Ctenoides mitis; Fig. 41) and large byssal gland at ‘heel’
from which emerges a thick bundle of strong byssal threads.
Ctenidia large, synaptorhabdic, pigmented yellow basally
and orange to reddish purple distally in living individuals,
accompanied by paired lips and labial palps. Visceral mass
containing stomach (type IV of Purchon 1957) dorsally,

Western Atlantic Limidae Invertebrate Systematics 673
narrowing ventrally to contain closed intestinal loop
(Fig. 39, in). Anal papilla hanging free posteroventrally
behind adductor muscle.
Manning and Kumpf (1959: 303; as Lima lima) described
the fecal pellets of this species as ‘rod-shaped … [and] …
circular in cross-section.’
Distribution
Bermuda, North and South Carolina, south-eastern to north-
western Florida and the Florida Keys, Texas, the Bahamas,
Greater and Lesser Antilles, Caribbean Central and South
America (to Brazil). Literature records from Sarasota,
Florida (Dall 1889, 1898), Costa Rica (INBio 2001;
Figs 4–11. The shells of western Atlantic Lima caribaea with, for comparison, those of similar worldwide Lima species.
4, L. caribaea, external (LV) and internal (RV) views of shell (Missouri Key, Florida Keys, FMNH 182935, 40.4 mm, 28 ribs);
5, L. caribaea, original figure by d’Orbigny (1842: pl. 28, fig. 17), c. 27 ribs; 6, L. caribaea, detail of sculpture (SEM) (Key Vaca,
Florida Keys, AMNH 247510); 7, L. caribaea, prodissoconch (SEM) (Dominican Republic, AMNH 94654); 8, L. lima, external
(LV) view (Naples, Italy, AMNH 111, 34.9 mm, 20 ribs); 9, L. vulgaris, external (LV) view (Great Barrier Reef, Australia, AMNH
249935, 50.7 mm, 17 ribs); 10, L. tetrica, external (LV) view (Sonora, Mexico, AMNH 131151, 22.3 mm, 21 ribs); 11, L. nimbifer,
external (LV) view (Port Jackson, Australia, AMNH 27081, 27.8 mm, 29 ribs). Scale bars = 500 µm (6), 50 µm (7).

674 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
Espinosa and Ortea 2001) and Venezuela (Work 1969; Rios
1994) have not been verified. Also from Miocene Chipola
Formation, Florida (Vokes 1973); Pliocene Caloosahatchie
marls, Florida (Dall 1898); Pleistocene, West Indies (Dall
1898) and northern Gulf of Mexico (Parker 1960; as
L. lima); Pleistocene, Cuba (Jaume and Pérez Farfante
1942). Parodiz (1976, as L. lima) reported L. caribaea in
Mayan archaeological sites in Yucatan.
Habitat and depth
Living individuals are found byssally attached to some sort
of rubblely substratum, e.g. under or among rocks or coral
(e.g. AMNH, HBOM, HMNS, UMML, ex Lloyd Collection;
Calkins 1878; Webb 1945; Abbott 1954, 1968, 1986; Stanley
1970; Waller 1973; Humfrey 1975; Rios 1994; Emerson and
Jacobson 1976; Lindner 1977; Hemmen and Hemmen 1979;
Vokes and Vokes 1984; Jensen and Harasewych 1986;
Lawson 1993; Redfern 2001; this study), calcareous algae
(UMML, Rios 1970), coarse sand (Waller 1973), empty
shells (Brooks, 1968) or sponges (AMNH, UMML, Rios
1970; this study). Two living specimens (FMNH 30323) from
Bermuda were taken from floating Sargassum. Andrews
(1994: 108) noted that it ‘occasionally comes to shore
attached to bamboo roots or coconuts.’ It was also listed as
abundant among species composing the community living
attached to the spines of thorny oysters (Bivalvia: Spondyl-
idae: Spondylus spp.; Plockelman 1970a), and as part of a
fouling community on salvaged anchors (Kennedy 1969).
Sand or mud has been given as its habitat (Dall 1886; Rios
1970; Waller 1973; Plockelman 1970b), although this in
most cases pertains to empty shells. Living specimens range
from the shallow subtidal to 311 m (UMML 30.11941), with
empty-shell or unspecified records encountered far deeper
(1075 fathoms or 1966 m; Smith 1885). In the Florida Keys,
this species is restricted to the oceanside of the island chain
(a single record, FK–204, from a locality not fully oceanic, is
from a mangrove creek off an interisland channel).
Remarks
This well known form is usually labelled Lima lima (Linné,
1758), in western Atlantic literature and collections. L. lima
was originally described (Linné 1758: 699, sp. 175, as
Ostrea) from ‘O. meridionali’ (=Southern Sea). Although
this locality indication has been called ‘almost completely
uninformative’ (Dodge 1952:186), it has been interpreted by
most authors as southern European or Mediterranean
(Bucquoy et al. 1888; Sowerby 1872; Gardner 1926;
Hertlein and Strong 1946; Dodge 1952; Stuardo 1968).
Similar shells (‘cognates’ of Barfield 1990; ‘analogues’ of
Odé 1979) from the Red Sea and Indo-Pacific localities refer
to the nominal species L. vulgaris (Link, 1807) (=L. sowerbyi
Deshayes, 1863, non Geinitz, 1850; fide Cernohorsky, 1972;
Fig. 9); those from the eastern Pacific are assigned to
L. tetrica Gould, 1851 (Fig. 10).
The conspecifity of eastern and western Atlantic popu-
lations of ‘Lima lima’ has long been a matter of dispute.
Dodge (1952: 187) ‘examined a considerable series of
specimens labelled ‘lima’ from the western Atlantic and
from the Mediterranean Sea, and [could] find no difference
that would justify their specific or even subspecific separa-
tion.’ Lamy (1930) distinguished several forms and varieties
of L. lima (most of which are now treated as full species) on
the basis of their rib counts. Both eastern (AMNH 290385,
Spain; AMNH 107643, Italy) and western Atlantic speci-
mens (FK, this study) have prodissoconch diameters of
c. 200 µm.
Nevertheless, others (including this analysis) have found
consistent differences in rib number between various world-
wide populations. Specimens of Lima lima from the Red Sea
and Mediterranean are usually cited or illustrated with
11–18 (Oliver 1992: pl. 14, figs 6a, c) and 18–25 ribs
(Sowerby 1843: 85, figs 1, 18; Poppe and Goto 1993; Fig. 8),
respectively. Vokes (1973: table 1) ‘tentatively’ recognised
western Atlantic specimens of ‘L. lima’ as a distinct species
(=L. caribaea) on the basis of a consistently greater total rib
number (range 24–32, mean 27.1 ± 1.7 s.d., n = 75; Table 1).
L. caribaea was originally figured from Cuba with c. 28 ribs
(d’Orbigny 1842: pl. 28, fig. 17; later given in text as 32–33
ribs; d’Orbigny, 1846: 354; 1853: 337); this name has
usually been considered a junior synonym of L. lima (e.g.
Abbott 1954, 1974; Rios 1994; Jensen and Harasewych
1986; Diaz Merlano and Puyana Hegedus 1994); Dall
(1886) called it a ‘condition’ of young L. squamosa
Lamarck, 1801 [now considered a synonym of L. lima; the
best illustration cited by Lamarck (his pl. 206, fig. 4, of
1787), is based on a specimen with only 18 ribs, excluding it
from the western Atlantic fauna; see below]. The original
description of L. lima gave a total rib number of 22,
supporting the opinion that Linné’s original material was not
from the western Atlantic. Our observations (Table 1; also
Tornaritis 1987: 20 ribs) support Vokes’s data in considering
the western Atlantic species distinct from other members of
the complex (L. lima, L. vulgaris, L. tetrica) although
specimens with 22–23 ribs are occasionally encountered.
We here use L. caribaea as the name for the western Atlantic
species with 22–34 ribs (mean 27.3 ± 2.1 s.d., n = 287),
yielding figures closely overlapping with Vokes’ (1973) data
though based on a substantially greater number of speci-
mens. Such separation on the basis of rib number has also
been used (Raines 2002) to distinguish L. profunda
Masahito, Kuroda & Habe, 1971, of Japan from a new
species, L. disalvoi Raines, 2002, of Easter Island. The name
L. caribaea was also used for western Atlantic forms by
Sander and Lalli (1982), Vokes and Vokes (1984), Odé
(1988), Abbott and Morris (1995, as L. lima caribaea), and
Goto and Poppe (1996 as L. lima caribaea). Stuardo (1968:
67, 70, 73) used L. lima and L. caribaea as name bearers for
his two Lima species groups, based on less or more than

Western Atlantic Limidae Invertebrate Systematics 675
Table 1. Number of ribs on main body of valve for ‘Lima lima’ complex (incl. lima, caribaea, vulgaris, tetrica, nimbifer) from worldwide localities
Vokes (1973: table 1) data contrasted with specimens from this study.
Number of ribs
Locality (Species) Source 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 Nx ± s.d.
W Atlantic (L. caribaea) Vokes 1973 1 11 22 17 87531 75 27.1 ± 1.7
W Atlantic (L. caribaea) This study 2* 3* 5 1 15 31 44 65 52 37 18 10 3 2 4 287 27.3 ± 2.1
Bermuda 2233755 24 33 29.6 ± 2.5
Carolinas 1 1 2 26.0 ± 1.0
Florida 1* 2* 6 6 6 13 6 3 2 42 26.6 ± 1.6
Florida Keys 2 1 6 16 18 25 20 11 3 102 26.7 ± 1.7
Texas 3 1 4 29.2 ± 0.4
Bahamas 1 8 8 10 4 2 1 1 35 27.6 ± 1.6
Caribbean 1* 1* 2 2 6 9 14 13 9 4 4 2 65 27.5 ± 2.1
Brazil 1 1 1 1 4 26.2 ± 2.9
E Atlantic (L. lima) This study 1 2 1 2 1 7 21.9 ± 1.5
Mediterranean Sea (L. lima) Vokes 1973 2 1 1 4 21.3 ± 1.3
Mediterranean Sea (L. lima) This study 1 7 18 11 9 8 2 56 20.9 ± 1.4
Indian Ocean (L. vulgaris) Vokes 1973 2 5 2 9 21.0 ± 0.7
Indian Ocean (L. vulgaris) This study 1 11 5 4 2 1 6 1 31 20.5 ± 2.9
Philippines (L. vulgaris) Vokes 1973 3 2 5 19.4 ± 0.5
Philippines (L. vulgaris) This study 1 4 13 7 1 26 21.1 ± 1.0
Japan (L. vulgaris) This study 7 1 6 3 17 19.3 ± 1.2
Australia (L. vulgaris) Vokes 1973 3 1 4 18.2 ± 0.4
Australia (L. vulgaris) This study 1 1 6 2 4 1 15 18.9 ± 2.0
Other W Pacific (L. vulgaris) This study 2 4 8 6 8 5 33 19.9 ± 1.5
E Pacific (L. tetrica) This study 2 12 13 9 4 40 20.0 ± 1.1
Indo-Pacific (L. nimbifer) This study 1 313261 17 29.4 ± 1.8
N, Total number; s.d., standard deviation; x, mean number of ribs; *, exceptions to typical-caribaea rib count, not included in total or mean.

676 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
25 ribs, respectively, plus differences in body size and
robustness of sculptural features.
Total rib counts from descriptions or images in the
western Atlantic literature include: 23 (Vokes and Vokes
1984: pl. 37, fig. 3); 24 (Tryon, 1873–1874: pl. 44, fig. 544;
Smith 1945: cited as 20–24 [but including Mediterranean
Lima lima]), 25 (Warmke and Abbott 1961: fig. 34f; Andrews
1994: 107, fig.; Redfern 2001: pl. 85, fig. 850), 26 (Humfrey
1975: pl. 27, fig. 9; Rios 1994: fig. 1188, cited as 25–32); 27
(Abbott and Morris 1995: pl. 26, fig. 10; Emerson and
Jacobson 1976: pl. 39, fig. 21); 28 (Webb 1935: 64, text-fig.;
Rice and Kornicker 1962: 381; Abbott 1968: 213, text-fig. 5;
Diaz Merlano and Puyana Hegedus 1994: pl. 10, fig. 95,
cited as 25–32); 29 (Abbott 1954: fig. 35 g; McLean 1951:
pl. 7, fig. 3; Pointier and Lamy 1998: 188, text-fig.); 31
(Stanley 1970: pl. 13, fig. 10; Jensen and Harasewych 1986:
text-fig. 157, cited as 26–33), 32 (Abbott 1986: fig. 5), and 33
(Lawson 1993: text-fig., cited as 26–33).
Exceptions below the minimal rib count of Lima
caribaea are known. One of the popular Peterson Field
Guides featuring western Atlantic molluscs (Morris 1973:
33, pl. 18, fig. 5) illustrated and indicated ‘~20’ ribs. Five
such specimens in western Atlantic museum lots were
recorded during this study: AMNH 292005 (two specimens;
19 and 20 ribs), DMNH 7656 (20 ribs; figured by Abbott
1974: pl. 20, fig. 5240), FMNH 155214 (19 ribs), USNM
406980 (20 ribs) are of rib numbers normally associated
with non-western Atlantic forms (Table 1, asterisks).
Stuardo (1968: 82) apparently also noted this, as evidenced
by his (unexplained) notation, ‘occasional in the Caribbean
?,’ under L. lima. Webb (1945: pl. 12, fig. 2) illustrated a
valve with 18 ribs. The status of these specimens (true
exceptions? questionable locality data?) is uncertain.
One nominal species in the Indo-Pacific, Lima nimbifer
Iredale, 1924 (=L. multicostata Sowerby, 1843, non Geinitz,
1839; type species of the nominal genus Austrolima), has a
rib count (26–32, mean 29.4 ± 1.8 s.d., n = 17) equal in
magnitude to that of L. caribaea (Table 1; Fig. 11).
Sowerby’s (1843: 85, fig. 38) original description of Lima
multicostata indicated 35–36 ribs. Smith (1885) and Lamy
(1930) considered L. caribaea as indistinguishable from
L. multicostata, and treated the former as a junior synonym.
Aguayo and Jaume (1948) recognised L. multicostata in the
Caribbean as a form of L. lima. Lima nimbifer (as multi-
costata) was also listed as a form or subspecies (along with
L. caribaea and others) of L. lima by Abbott (1954, 1974)
and by Jensen and Harasewych (1986), but in view of the
greatly disjunct distributions we prefer to retain it as distinct
until more detailed comparative studies can be made.
Lima caribaea has usually been described as ‘pure white’
(e.g. Webb 1945; Abbott 1954; Rice and Kornicker 1962;
Emerson and Jacobson 1976), but this refers to the shell
only. Living specimens observed during this study showed
dark-coloured (orange to reddish purple) flames on the
pallial veil, gills grading from yellow at the axes to dark-
coloured distally, dark-coloured bands on the foot and
rectum, and white tentacles with black eyes among the dark-
coloured tentacle bases. No remnant of colour or colour
pattern is retained in specimens preserved in alcohol.
Simpson (1887–1889: 70) described the animal as ‘purplish
crimson.’ Humann (1992: 248–249, repeated by Humann
and DeLoach 2002: 326–327, both as L. lima) described the
tentacles as white to lavender, and figured a specimen with
dark red-purple tentacles and mantle.
Lima marioni P. Fischer
Marion file clam
(Figs 12–14)
Lima marioni P. Fischer, 1882: 52. – Locard 1898: 410–411 (with
named varieties major, intermedia, depressa, elongata,
rotundata), pl. 15, figs 15–19 (in part); Dautzenberg 1927:
247–248; Nordsieck 1969: 58–59, pl. 10, fig. 36.21; Glémarec
1978: 26, Table 2; Oliver 1987: 1; Martínez et al. 1993: 69,
fig. T; Poppe and Goto 1993: 77; Goto and Poppe 1996: 1: 488,
2: 897; Mikkelsen and Bieler 1998: 223; Rolán et al. 1989: 102,
text-fig.
Lima (Radula) marioni. – Thiele 1918: 16–17, pl. 3, figs 6–8
(=reproduction of Smith’s lata figs).
Lima lata Edg. Smith, 1885: 287–288, pl. 24, figs 3, 3a (in part, see
below). – Rios 1975: 210.
Lima (Lima) lata. – Aguayo and Jaume 1948: 1.
Radula lata. – Dautzenberg and H. Fischer 1897: 186.
Lima new species (manuscript name) Stuardo 1968 [unpublished
dissertation]: 95, pl. 4, fig. 21.
Material examined
Type material.Lima marioni: 2 syntypes (one pair with partial
dried soft parts, 1 RV) (MNHN; Fig. 12); the type locality is off western
Portugal, 1068 m [41°43′N, 009°19′W, 14.vi.1881, Expedition du
Travailleur sta. DR02], by original designation. Lima lata: lectotype
(here selected), figured specimen (Smith, 1885: pl. 24, figs 3, 3a), mid-
Atlantic Ocean, St Paul’s Rock, 104 fathoms (190 m), Challenger
Expedition sta. 109 (42.4 mm, 32 ribs, dry pair [vidi] plus body in alco-
hol collection, BMNH 1887.2.9.3218); the type locality is Rocedos de
São Paulo (St Paul’s Rocks), Brazil, by subsequent restriction (herein,
see below).
Other material examined.Brazil: 7 LV, 1 RV, off São Luis (USNM
811223; Fig. 13). Azores: 4 pair (all with dried anatomy), off Graciosa
(MNHN). British Isles: 13 pair (all with at least partial dried anatomy),
Mer Celtique (MNHN).
Diagnosis
Shell whitish, heavy, broadly pecten-shaped, with 31–37
scaly radial ribs; interspaces with close transverse scratches.
Prodissoconch 285–300 µm. Animal (from dried soft parts)
with single row of short pallial tentacles; colour in life
unknown.
Description
Shell whitish (or grey dead-collected), 25–30 mm (range
9–42.4 mm, mean 26.9 ± 7.5 mm s.d., n = 28), relatively

Western Atlantic Limidae Invertebrate Systematics 677
thick-shelled, equivalve, inequilateral, rounded triangular to
circular in outline (Figs 12–13). Compressed laterally, very
narrowly gaping anteriorly (byssal gape); posterior margin
not gaping. External shell surface sculptured with 31–37
smooth to scaly radial ribs (mean 33.5 ± 1.8 s.d., n = 27), not
divaricating, plus closely set transverse scratches in the
interspaces (Fig. 14). Posterior auricle extending ‘normally,’
anterior auricle ‘hidden’ from dorsal view below strongly
demarcated, oblique anterodorsal ridge (called the ‘lunular
border’ by Stuardo 1968) adorned with 5–7 finer radial ribs.
Umbones central, small, extending as minute points above
the hinge line. Prodissoconch as in L. caribaea, 285–300 µm
in maximum length (MNHN, n = 2). Hinge line narrow,
obliquely skewed posterolaterally, with a shallow, central,
triangular resilifer. Hinge teeth consisting of small elon-
gated tubercles at lateral ends of hinge line in LV, articu-
Figs 12–14. Lima marioni. 12, External (RV) and internal (LV) views of paired syntype (western
Portugal, MNHN, 11.4 mm, 35 ribs); 13, external and internal views of western Atlantic specimen
(LV, Brazil, USNM 811223, 24.3 mm, 34 ribs); 14, detail of Fig. 13 showing shell sculpture, with
scaled ribs and transverse scratches in interspaces; scale bar = 2.0 mm.

678 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
lating with shallow elongated depressions at lateral ends of
hinge line in RV; anterior tubercle (at dorsal end of flaring
byssal gape) somewhat larger. Inner margin crenulated,
reflecting exterior ribs. Pallial line simple, entire. Mono-
myarian; adductor muscle scar posterior, with pedal retrac-
tor muscle scar immediately ventral to it; pedal protractor
muscle scar tiny, central and just below umbo. Periostracum
thin, light tan to golden yellowish.
Animal (observed from dried soft parts, MNHN) with
single row of short pallial tentacles and typical ctenidia,
muscles and foot; presence of eyes unclear; colour in life
unknown.
Distribution
Mid-Atlantic Ocean, off both western and eastern Atlantic
(France to Sudan) coastlines; northernmost extent off the
southern British Isles to southernmost extent off north-
eastern Brazil. Literature records from off Yucatan (Stuardo
1968), Cuba (Aguayo and Jaume 1948), and eastern Atlantic
localities (Locard 1898; Thiele 1918; Stuardo 1968;
Glémarec 1978; Oliver 1987; Rolán et al. 1989; Martínez
et al. 1993; Poppe and Goto 1993) have not been verified.
No fossil record known.
Habitat and depth
Apparently restricted to deep water; verified live-collected
specimens from 400–1068 m. Other records are from
191–1710 m. Recorded habitats are sand, mud, gravel and
rocks (Stuardo 1968) or ‘on coral’ (Rolán et al. 1989).
Remarks
This species has a wide, amphiatlantic distribution. From
the limited number of specimens available, the number of
ribs is comparable in both eastern and western Atlantic
populations.
Stuardo’s unpublished study (1968) included this species
in a new subgenus of Lima, with the Indo-Pacific species
L. tomlini Prashad, 1932, as its supposed type. The group
was said to be based on the extremely skewed hinge line
(referred to as ‘rotation of the hinge towards the anterior
(and ventral) part of the shell’; Stuardo 1968: 87). Although
he recognised Atlantic specimens from off the coasts of
Brazil, Africa and Portugal as conspecific, he named a single
small specimen from off Yucatan, Mexico (MCZ 7821,
640 fathoms [1170 m], 12.8 mm, 34 ribs; Stuardo 1968:
pl. 4, fig. 21) as distinct from L. marioni (the latter indicated
as ‘not seen’), describing its shell as having a shorter, more
concave lunular border, a comparatively thicker shell, and
flat ribs with few spines. Based on the range of variation in
the material examined here, we consider the Caribbean form
to be conspecific with L. marioni.
Smith (1885) based his species Lima lata [not to be
confused with tentatively introduced ‘Limaea lata’ of Dall
(1886: 227)] on a paired 42.4 mm (largest recorded thus far)
specimen from St Paul’s Rocks, Brazil (BMNH
1887.2.9.3218), and a ‘few’ small specimens from the
Philippines (W side of Mindanao, 83 fathoms (152 m),
Challenger Expedition sta. 201: two fresh pairs, 12.8 and
14.0 mm, 28 ribs each, BMNH 1887.2.9.3216–7, vidi; also
two specimens in alcohol, BMNH 1889.11.11.148–9, not
seen). Both Atlantic and Philippines records have been
repeated by subsequent authors (Locard 1898; Thiele 1918;
Aguayo and Jaume 1948). Stuardo (1968: 320, unpublished)
placed L. lata in the synonymy ex parte of both Atlantic
L. marioni and Indo-Pacific L. tomlini. We here formally
designate Smith’s figured specimen (BMNH 1887.2.9.3218)
as lectotype of L. lata and correspondingly restrict its type
locality to Rocedos de São Paulo (St Paul’s Rocks),
Challenger Sta. 109. The other syntypic lots from
Challenger Sta. 201 (BMNH 1887.2.9.3216–7 and
1889.11.11.148–9) are not conspecific with the new lecto-
type of L. lata, being probably attributable to L. tomlini or
other related Indo-Pacific species awaiting revision (see
Stuardo, 1968). The anatomy of L. lata was described
previously by Pelseneer (1911: pl. 10, fig. 3), however these
data, based on Siboga Expedition material in the Indo-
Pacific, are attributable to L. tomlini (or related species) and
not to L. marioni.
Genus Ctenoides Mörch
Ctenoides ‘Klein’ Mörch, 1853: 56–57.
Ctenoides Klein, 1753: 134–135 [pre-Linnean].
Divaricolima Rovereto, 1898: 153, 167.
Type species
Ostrea scabra Born, 1778, by subsequent designation
(Stoliczka 1871: xxii). The type species of Divaricolima
Rovereto (originally a section of Lima) is Lima eximia Giebel,
1864 (Oligocene of Germany), by original designation.
Diagnosis
Shell white, overlain with light brown, closely adherent
periostracum; gaping anteriorly (byssal gape, with thickened
edge) and more narrowly posteriorly. Sculpture of radial
ribs, divaricating at mid-valve, formed by overlapping
elongated plates, each ending in a pointed scale. Hinge line
relatively narrow. Inner shell margin smooth. Animal with
multiple rows of non-annulated pallial tentacles, the
interiormost relatively long, that are basally widened and
longitudinally grooved. Visceral mass with ventral extension
containing wide, 8-shaped intestinal loop.
Remarks
Klein’s (1753) pre-Linnean introduction of Ctenoides
referred to several published illustrations, including Lister’s
1685 figure upon which (in part) the species name C. scaber
(see below) was originally based.

Western Atlantic Limidae Invertebrate Systematics 679
Some authors (e.g. Hesse 1928: 853) have credited the
name Ctenoides to Deshayes. However, Deshayes merely
discussed (and dismissed) the use of Ctenoides by Klein
without making the name available, writing ‘Cténoïdes.
Under this name Klein […] had separated from the Comb-
shells of Linné some shells whose reunion in a separate
genus he considered useful. Since then, Bruguière re-
established them under the name Lime [French vernacular
for Lima]. This genus was adopted by Mr. Lamarck and the
greatest number of the zoologists’ (Deshayes 1830: 33; here
translated). Agassiz (1848), Bronn (1848) and Scudder
(1882) each credited Ctenoides to Agassiz (1834) who had
used the name for a group of fishes. Ctenoides of Agassiz,
however, was used only as a higher group name, and thus
does not impact taxonomy at the genus-group level.
Ctenoides was introduced by Mörch (1853: 56) as a
subgroup of Radula, adopting Klein’s name of 100 years
earlier, and referring to two nominal species, Ostrea scabra
Born, 1778, and ‘Lima tenera’ of Chemnitz, 1784; the latter
was an unavailable name (ICZN 1954), subsequently made
available as Lima tenera ‘Chemnitz’ Sowerby, 1843 (but
preoccupied by Lima tenera Turton, 1825); see also remarks
under C. mitis, below]. Mörch (1853) did not indicate the
gender of Ctenoides. Subsequent authors employed the
name variously as of male or female gender. According to
the ICZN (1999: Art. 30.1.4.4), a compound genus-group
name ending in the suffix -oides is to be treated as masculine
unless the author specified otherwise when establishing the
name, either by statement or by treatment in combination.
Ctenoides is here thus treated as masculine.
The following section covers all known western Atlantic
species of Ctenoides, e.g. the two species most frequently
acknowledged by checklists, C. scaber (type of the genus)
and C. mitis, two less well known species, C. planulatus and
C. sanctipauli, and three newly described species.
Ctenoides scaber (Born)
Rough file clam
(Figs 15–21, 44)
Ostra [sic] scabra Born, 1778: 96 [referencing Lister (1685: pl. 176,
fig. 13) and Knorr (1772: 73–74, pl. 38, fig. 5)].
Ostrea scabra. – Born 1780: 110–111; Dillwyn 1817: 271; Wood
1828: 51, pl. 11, fig. 55.
Lima aspera Chemnitz, 1784: 352–353, pl. 68, fig. 652
(unavailable; ICZN 1954: Direction 1).
Ostrea glacialis Gmelin, 1791: 3332 (not var. β, referring to
Chemnitz 1784: fig. 653 = C. mitis).
Ostrea sagrinata Humphrey, 1797: 52, no. 991 (unavailable; ICZN
1912: Opinion 51; 1956b: Direction 32).
Mantellum scabrum. – Röding 1798: 160 (in part, also referring to
C. floridana).
Lima glacialis. – Bosc 1802: 253 (in part, also referring to
Chemnitz 1784: fig. 653 = C. mitis); Lamarck 1819: 157 (in part,
not var. b = C. mitis; includes reference to Bruguière 1797:
pl. 206, fig. 2); Sowerby 1825: pl. 113, fig. 1; Wheatley 1842:
15; Wheatley 1845: 16; Beau in Petit de la Saussaye 1853: 416.
Lima asperula Lamarck, 1807 (January?): 462 (referring to
Chemnitz 1784: fig. 652).
Limaria asperula Link, 1807 (May): 157 (referring to Chemnitz
1784: fig. 652).
Lima scabra. – Anton 1838: 18; Sowerby 1843: 83–84, pl. 21,
Figs 4–5, 12; Catlow and Reeve 1845: 79; Schramm 1869: 23;
Sowerby 1872: pl. 2, fig. 8a, b; Tryon 1873–1874: 197, pl. 43,
fig. 543; Cockerell 1894: 113; Simpson 1887–1889: 70; Dall
1889: 36; Dall and Simpson 1901: 467; Thiele 1934: 811,
fig. 804; Aldrich and Snyder 1936: 34, pl. 3, fig. 23; Webb 1951:
61, pl. 21, fig. 4; Bartsch 1937: 22; Smith 1940: 97, text-fig.
1316; Jaume and Pérez Farfante 1942: 39 [Pleistocene]; Lyman
1944: 77; Smith 1945: 36, pl. 10, fig. 1; Rogers 1951: 410,
pl. 83, fig. 4 (as ‘scabra, Dillw[yn]’; corrected to Born by Rehder,
p. 502); Pulley 1952: 100, pl. 8, fig. 1; Hall 1952: 20, fig. 5;
Abbott 1962a: 133, Figs; Rice and Kornicker 1962: 381, pl. 7,
figs 4a–4b; Abbott 1968: 212–213, text-fig. 6b and unnumbered
colour drawing of living animal; Houbrick 1968: 19; Abbott
1970: 147, pl. 3b (in part); Magnotte 1970–1979: 74, text-fig. 6;
Stanley 1970: 142–143, pl. 13, Figs 5–8; Mpitsos 1973: 371 ff.;
Zeiller 1974: 56, text-fig.; Emerson and Jacobson 1976: 375,
pl. 39, fig. 22; Voss 1976: pl. 1 ; Lozet and Pétron 1977: 124,
fig. 232 (right only); Voss 1980: cover and plate facing p. 96;
Eisenberg 1981: 164, text-fig. 2; Rehder 1981: 695–696, fig. 462
(but not fig. 671); Kaplan 1982: 146; Sander and Lalli 1982:
Table 4; Kaplan 1988: 257, pl. 40, fig. 4: Turgeon et al. 1998: 27;
Abbott 1989: 63, text-fig.; Haywood and Wells 1989: 164, text-
fig.; Gordon 1990: 119, 121, text-fig.; Peeters and Exbrayat
1990: 20 (upper photo only); Lipe and Abbott 1991: 73 (upper
photo only); Humann 1992: 248–249 (upper text-fig. only);
Williams 1992: 12–13, text-fig.; Lawson 1993: cover fig., 48,
text-fig.; Gómez et al. 1995: 109 ff.; Pointier and Lamy 1998:
cover + 175, text-fig. (top); Porter and Houser 1998: 28, text-
fig.; Humann and DeLoach 2002: 326–327, text-fig. (in part,
with red tentacles); Invertebrate Biology, 121(4), 2002: cover.
Radula (Ctenoides) scabra. – Mörch 1853: 56; H. and A. Adams
1858: 557.
Lima (Ctenoides) scabra. – Dall 1898: 768; Johnson 1934: 26;
Jaume 1946: 99; McLean 1951: 35, pl. 7, fig. 2; Olsson and
Harbison 1953: 59; Abbott 1954: 370–371, pl. 35f, o; Warmke
and Abbott 1961: 171, pl. 34c; Abbott 1974: 453, pl. 20,
fig. 5242; Humfrey 1975: 231, pl. 27, fig. 7; Hemmen and
Hemmen 1979: 165; Vokes and Vokes 1984: 38, pl. 37, fig. 4;
Diaz Merlano and Puyana Hegedus 1994: 62, pl. 10, fig. 96, +
colour plate; Rios 1994: 243, pl. 84, fig. 1189; Lodeiros and
Himmelman 1999: 411 ff.
Lima inflata ‘Lamarck’ (misidentification; non Limaria inflata
Link, 1807, nec Ostrea inflata Gmelin, 1791). – Vilas and Vilas
1945: pl. 2, fig. 1.
Unidentified. – Abbott 1962b: 6 (as ‘lima clam,’ showing coarse ribs
and red tentacles); Ripple 1995: 33 (as ‘rough fileclam,’
showing red tentacles).
Lima scabra tenera (misidentification; non Lima tenera Sowerby,
1843). – Arnow et al. 1963: 170 (in part, with ‘pale orange
tentacles’).
Lima lima [misidentification; non Lima lima (Linné, 1758)]. –
Barrett and Patterson 1967: 55, text-fig. 1.
Ctenoides scabra. – Stuardo 1968: 116, pl. 2, fig. 16; Dance 1974:
240; Lindner 1977: 234, pl. 56, fig. 8; Odé 1979: 31–32; Oliver
1987: 1; Rosenberg 1992: 137, text-figs; Espinosa et al. 1994:
115; Goto and Poppe 1996: 1: 704, 2:896, ‘East America’;
Mikkelsen and Bieler 1998: 223; INBio 2001; Redfern 2001:
207–208, pl. 85, fig. 852A–B, colour pl. 124, fig. 852C.
Lima scabra scabra. – Morris 1973: 33, pl. 18, fig. 1; Abbott and
Morris 1995: 32, pl. 26, fig. 8; Lyons and Quinn 1995: J–11.

680 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
Ctenoides (Ctenoides) cf. scabra. – Vokes 1973: 91, pl. 1, fig. 2.
Lima scabra forma tenera (misidentification; non Lima tenera
Sowerby, 1843). – Abbott and Morris 1995: 32, pl. 4.
Ctenoides scaber. – Mikkelsen and Bieler 2000: 373; Lee 2002.
Ctenoide (sic) scabra. – Espinosa and Ortea 2001: 66.
Material examined
Type material. Born (1778) referred only to the previously pub-
lished figures of Lister (1685: pl. 176, fig. 13, as ‘pecten albus,
angustus…’; no corresponding specimen[s] in BMNH collections,
K. Way, personal communication 19.ii.2003) and Knor r (1772: 73–74,
pl. 38, fig. 5, as ‘Katzenzunge’), both of which are clearly referable to
C. scaber. Born did not mention any original material or any localities,
although he later (1780) listed Barbados and ‘S[ancti] Dominici’ (Santo
Domingo, an early name for the island of Hispaniola); to our knowledge
no subsequent author has further restricted the type locality and we con-
sider this action as unnecessary.
Selected other material examined.North Carolina: 2 pair (live-
collected), off Cape Lookout (NCSM IMS–7132); 1 V, s.e. of Cape Fear
(NCSM-IMS 2704). South Carolina: 1 alc (not seen) (USNM 847912).
Florida: 1 pair (live-collected; former size maximum, fig. 16), off May-
port (Lloyd Collection); 1 pair, Palm Beach (UMML 28.531); 1 pair,
North Lake Worth Inlet (AMNH 291999); 1 pair, Pompano Beach
(HMNS 23945); 4 pair, 1 V, Biscayne Bay (AMNH 198460); 1 pair,
Biscayne Bay (AMNH 115363); 1 pair, Biscayne Bay (AMNH 120543;
figured by Emerson and Jacobson 1976: pl. 39, fig. 22); 2 pair, Miami
(AMNH 115474); 4 pair, Soldier and Ragged Keys (USNM 701142;
Fig. 19); 1 pair, Old Rhodes Key (UMML 28.196); 1 pair, Key Largo
(AMNH 120544); 2 V, Triangles Reef (FK–164; FMNH 301258); 2
pair, Upper Matecumbe Key (AMNH 247501); 1 V, Upper Matecumbe
Key (DMNH 51286; largest recorded specimen); 2 pair, Duck Key
(AMNH 247498); 1 pair, Tom’s Harbor (AMNH 292010); 2 pair, Mar-
athon, Key Vaca (AMNH 247497); 1 alc, East Washerwoman Shoal
(FK–115; FMNH 301263); 1 V, Marathon, Key Vaca (FK–121; FMNH
301257); 1 alc, Marathon, Key Vaca, bayside (FK–118; FMNH
301264); 7 pair, Pigeon Key (FMNH 182936; Fig. 15); 5 alc, Ramrod
Key (FK–047; AMNH 232698/232699); 6 alc, 3 pair, 2 V, Ramrod Key
(FK–069; AMNH 232697); 2 alc, 2 V, Spanish Harbor Keys, bayside
(FK–244; FMNH 301259/301260); 42 pair, Key West (FMNH
182938); 1 pair, 1 V, Key West (CMNH); 1 pair, Dry Tortugas (USNM
458269); 3 pair, Dry Tortugas (UMML 28.798); 13 V, Dry Tortugas,
Hospital Key (FK–601; AMNH 308076); 2 V, Dry Tortugas, Logger-
head Key (FK–092; FMNH 301253); 1 pair, Sanibel Island (AMNH
131887); 1 alc, off Apalachee Bay (FMNH 57046). Texas: 1 V, off Free-
port (ANSP 338421). Mexico: 1 pair, off Tampico (USNM 710320); 2
pair, off Vera Cruz (HMNS 18210). Belize: 1 V, Stann Ck (USNM
770992); 1 pair (HMNS 8416); 1 alc, South Water Cay (HBOM
064:01081). Honduras: 1 pair, Islas de la Bahía (HMNS 8205).
Panama: 1 RV, Bocas del Toro (UMML); 2 pair (plus photo, live-col-
lected), San Blas Islands (Lloyd Collection). Bahamas: 1 V, North
Bimini (AMNH 87267); 3 V, New Providence Island (FMNH 293002);
2 pair, Nassau (AMNH 27068); 1 pair, Grand Bahama Island (AMNH
121335); 2 juv alc, Hogsty Reef (HBOM 064:01727); 2 V, Andros
(AMNH 307195). Cuba: 1 pair, Guantanamo (USNM 487739). Cay-
man Islands: 2 V, Grand Cayman Island (AMNH 89511); 1 alc, Grand
Cayman Island (AMNH 182648). Jamaica: 1 pair, Kingston (AMNH
141894); 1 alc (AMNH 295375); 1 alc (UMML 30.11875). Hispan-
iola: 1 V, Haiti (UMML 28.16123); 5 pair (live-collected), Dominican
Republic (AMNH 94655; Fig. 21); 6 valves, north coast of Peninsula
Samaná (MTD 42152; K. Schniebs, personal communication); 1 alc,
Santo Domingo (AMNH 179525). Puerto Rico: 1 pair, Parguera
(AMNH 522); 4 pair, southern Puerto Rico (FMNH 278509;
Figs 17–18). Virgin Islands: 1 pair, St John (UMML 28.657); 1 pair, St
Thomas (AMNH 182050); 1 V, Nevis (Hewitt Collection); 1 juv alc
(UMML 30.11871). Anguilla: 1 V (AMNH 292001). Guadeloupe: 1
alc (UMML). St Vincent: 1 alc, Old Woman Point (HBOM 064:02308).
Grenadines: 1 V, Carriacou (FMNH 278510). Tobago Island: 11 V
(AMNH 85361). Colombia: 1 pair, Rosario Islands (FMNH 101306).
Venezuela: 2 pair, Isla Margarita (AMNH 221714); 1 pair, Magdalena
(HMNS 25246); 6 alc, Naiguata (UMML 30.11876). Netherlands
Antilles: 1 pair, Bonaire (AMNH 247516); 1 V, Curaçao (FMNH
12759); 1 juv alc (UMML 30.11872).
Diagnosis
Shell white with light brown periostracum, oval, anteriorly
and posteriorly gaping, with c. 50 scaly radial ribs and
transversely grooved interspaces. Prodissoconch 170 µm.
Animal with long, reddish-orange pallial tentacles; mantle,
gills, and smooth pallial veil reddish-orange.
Description
Shell whitish, c. 50 mm (range 9.8–107.2 mm, mean 53.3 ±
18.6 mm s.d., n = 217; previously recorded maxima
105.0 mm by Hutsell et al. 1997 [as 106.0 mm, Lloyd
Collection, vidi] and 66 mm by Porter 1971 [NCSM-IMS
2704, verified by A. Bogan]), relatively thick-shelled, equi-
valve, equilateral, elongated oval in outline. Moderately
compressed laterally, gaping anteriorly (byssal gape) and
more narrowly posteriorly. External shell surface sculptured
with scaly radial ribs (range 28–78, mean 55.1 ± 17.1 s.d.,
n = 198), divaricating at mid-valve to increase in number
with increasing shell height, plus closely set, slightly
slanting, transverse grooves in interspaces (Fig. 21). Auricles
moderately demarcated from body of shell, each adorned
with 5–8 radial ribs; anterior auricle somewhat distorted by
thickened anterior edge of byssal gape. Umbones central,
small, extending slightly above the hinge line. Prodisso-
conch smooth, D-shaped, 170 µm in maximum length
(AMNH, n = 1), bounded from teleoconch by distinct double
growth line (as in C. mitis; Fig. 26). Hinge line narrow, with
a shallow, central, triangular resilifer. Hinge teeth consisting
of small elongated tubercles at lateral ends of hinge line in
LV, articulating with shallow elongated depressions at lateral
ends of hinge line in RV; anterior tubercle (at dorsal end of
flaring byssal gape) somewhat larger. Inner margin smooth.
Pallial line simple, entire. Monomyarian; adductor muscle
scar posterior, with slightly smaller pedal retractor muscle
scar ventral and slightly medial to it (Fig. 20); pedal
protractor muscle scar tiny, central and just below umbo.
Periostracum light brown, closely adherent.
Shell gaping 25–40º in living individuals at rest. Animal
(Fig. 40) with multiple rows of papillose (but non-
annulated) pallial tentacles, the innermost relatively long.
Eyes dark red-orange (16 per side in 35.2-mm specimen,
FK–118), evenly dispersed at mantle edge between tentacle
bases, each surrounded by area of translucent tissue.
Extensive pallial veil (=curtain) smooth to finely granular
(but not papillose), extending from mantle edge inside
tentacle rows to fully span opening of normally gaping shell

Western Atlantic Limidae Invertebrate Systematics 681
Figs 15–21. Ctenoides scaber. 15, External (RV) and internal (LV) views of shell (Pigeon Key, Florida Keys, FMNH 182936,
76.2 mm); 16–19, additional external views, showing variation in shape, from 16, off Duval County, Florida (LV, Lloyd
Collection, 105.0 mm), 17, Puerto Rico (LV, FMNH 278509, 61.0 mm), 18, Puerto Rico (LV, FMNH 278509, 56.0 mm),
showing slender morphology on anterior margin, 19, Soldier/Ragged Keys, Florida (LV, AMNH 701142, 59.5 mm), showing
change from slender to normal morphology; 20, interior view of LV, showing pallial line and muscle scars (am, adductor
muscle; prm, pedal retractor muscle); 21, detail of sculpture (SEM) showing scales, transverse grooves in interspaces, and mid-
valve divarication (Dominican Republic, AMNH 94655); scale bar = 500 µm.

682 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
when alive. Tentacles, mantle, gills, and veil orange to bright
red in living adults (Fig. 44); single juvenile observed with
tentacles, veil and gills light orange with red bands on
tentacles and red flames on veil (FK–115, 9.8 mm). Ctenidia
expansive, synaptorhabdic, more lightly pigmented at axes
grading to red distally, accompanied by complex paired lips
(as in C. mitis, Fig. 47) and labial palps. Visceral mass
yellow-orange with reddish mottlings, containing stomach
(type IV of Purchon 1957) dorsally, broadening ventrally to
contain wide, 8-shaped intestinal loop (Fig. 40, in). Foot
relatively large, red in living individuals, with unpigmented,
transversely ridged ‘sole’ at tip (as in C. mitis; Fig. 41) and
large byssal gland at more dorsal ‘heel’ from which emerges
a thick bundle of strong byssal threads. Anal papilla hanging
free posteroventrally behind adductor muscle.
The anatomy of Ctenoides scaber was described previ-
ously by Stuardo (1968), with additional details of lip and
foot morphology provided by Gilmour (1974, 1990, respec-
tively). The species is a protandric hermaphrodite (Lodeiros
and Himmelman 1999). Mpitsos (1973) investigated the
visual physiology of C. scaber as related to its response to
predators.
Distribution
North and South Carolina, both coasts of Florida (including
the Florida Keys), Texas, Bahamas, Greater and Lesser
Antilles, Caribbean Central and South America (to Vene-
zuela, unverified to Brazil). Literature records from Costa
Rica (Houbrick 1968; INBio 2001; Espinosa and Ortea
2001), Barbados (Dillwyn 1817; Sander and Lalli 1982) and
Brazil (Rios 1994; Abbott 1974; Hemmen and Hemmen
1979; Eisenberg 1981; Rehder 1981; Kaplan 1988;
Rosenberg 1992; Lawson 1993; Diaz Merlano and Puyana
Hegedus 1994; Abbott and Morris 1995) have not been
verified. Also from Late Tertiary, Bahamas (with blister
pearls; Jackson 1909; Dartevelle 1934; Brown 1940),
Miocene Chipola Formation, Florida (Vokes 1973), Pliocene
Caloosahatchee Formation, Florida (HBOM; Dall 1889,
1898; Olsson and Harbison 1953; Brayfield and Brayfield
1993), and Pleistocene, South Carolina and West Indies
(Dall 1898) and Cuba (Jaume and Pérez Farfante 1942).
Parodiz (1976) reported C. scaber in Mayan archaeological
sites in Yucatan. Further information is available as Acces-
sory Material on the Invertebrate Systematics website.
Habitat and depth
Living individuals are found byssally attached to hard or
rubblely substratum, e.g. under or among rocks or coral
(AMNH, UMML; Calkins 1878; Simpson 1887–1889;
Abbott 1954, 1974; Warmke and Abbott 1961; Rios 1994;
Stanley 1970; Humfrey 1975; Hemmen and Hemmen 1979;
Rehder 1981; Lawson 1993; Porter and Houser 1998;
Lodeiros and Himmelman 1999; this study), on wrecks
(HBOM; Porter and Houser 1998), and especially in
crevices of reefs and ledges (Lloyd Collection; Bartsch
1937; Lyman 1944; Vokes and Vokes 1984; Williams 1992;
Diaz Merlano and Puyana Hegedus 1994; this study). In the
Florida Keys, it often co-occurs with C. mitis. Living
specimens range from the shallow subtidal (this study) to
48 m (USNM 847912, not seen), with empty-shell or
unspecified records encountered far deeper (221 m; Dall
1889). Ring (1980) called it ‘nocturnal,’ taking refuge under
rocks during daylight hours. Gómez et al. (1995) reported
on its ecology in a coastal coral reef off Venezuela and found
a mean density of ~9 individuals per square metre. Read
(1967), working with shallow-water (0.5 –1 m) Puerto Rican
specimens, investigated long-term thermal tolerance and
concluded that temperatures above 33°C are not likely to be
survived for extended periods. This is corroborated with
observations in this study: living specimens of Ctenoides
were only found in highly modified parts of Florida Bay and
never in the sun-baked shallows. C. scaber was restricted to
two such sites: an abandoned boat channel on the bayside of
Stirrup Key (near Marathon, Key Vaca) and ‘The Horse-
shoe,’ a former mooring site created and used during
construction of the Overseas Highway bridges. Both of these
sites have relatively vertical coral-rock walls in water much
deeper than is typical for the bayside (by human alteration of
the seabed) that provide suitable habitat (and more ‘oceanic’
conditions) for C. scaber.
Remarks
This species has long been known to science, having been
illustrated and described, from unspecified locations, in the
pre-Linnean literature. It was first validly described, as
Ostr[e]a scabra, by Born (1778); Ostrea glacialis Gmelin,
1791, as well as Lima aspera Lamarck, 1807 (and the near-
simultaneoulsy introduced Limaria asperula Link, 1807) are
synonyms. Other early names introduced for it by
Humphreys (1797, ‘Ostrea sagrinata’) and Chemnitz (1784,
‘Lima aspera’) are not available for nomenclatorial purposes.
Stuardo (1968) noted that no other species of Ctenoides
has the coarse spiny rib-scales and large body size of
C. scaber. See additional comparative remarks under the
description of C. mitis.
Ctenoides mitis (Lamarck)
Smooth file clam
(Figs 22–26, 41–42, 45–47)
Lima mitis Lamarck, 1807 (January?): 463 (referring to Chemnitz
1784: fig. 653).
Lima tenera Chemnitz, 1784: 354–355, pl. 68, fig. 653 (unavailable;
ICZN 1954: Direction 1).
Ostrea glacialis [var.] β – Gmelin 1791: 3332;
Ostrea sagrinata var. Humphrey, 1797: 52, no. 991 (unavailable;
ICZN 1912: Opinion 51; 1956b: Direction 32).
Mantellum scabrum. – Röding 1798: 160 (in part, also referring to
C. scaber).

Western Atlantic Limidae Invertebrate Systematics 683
Lima glacialis. – Bosc 1802: 253 (in part, also referring to
Chemnitz 1784: fig. 652 = C. scaber).
Limaria mitis Link, 1807 (May): 157 (referring to Chemnitz 1784:
fig. 653).
Ostrea glacialis var. – Dillwyn 1817: 272.
Lima glacialis var. [b] – Lamarck 1819: 157 (includes reference to
Bruguière 1797: pl. 206, fig. 3); Schramm 1869: 23.
Lima scabra V[ar]. b – Anton 1838: 18.
Lima tenera ‘Chemnitz’ Sowerby, 1843 (non Lima tenera Turton,
1825): 84, pl. 21, figs 10, 11 (cited figs 2, 3, 13 here excluded).
– Catlow and Reeve 1845: 80 (in part, also includes Indo-Pacific
form); Sowerby 1872: pl. 2, fig. 7; Dall 1886: 224; Simpson
1887–1889: 70; Dall 1889: 36; Maury 1920: 63; Webb 1951: 64,
pl. 22, fig. 20; Smith 1940: 96, text-fig. 1318; Jaume and Pérez
Farfante 1942: 39 [Pleistocene]; Smith 1945: 36, pl. 10, fig. 14,
pl. 13, fig. 14 [this figure mislabelled L. inflata (=Limaria
pellucida) in 1937 ed.]; Pulley 1952: 100, pl. 8, fig. 2; Parker
1960: 325, pl. 6, fig. 30; Odé and Speers 1965: 3; Lipka 1974:
160, text-figs 87–88; Wye 1991: 247, text-fig.; ITIS 2002b.
Radula (Ctenoides) tenera. – Mörch 1853: 56; H. and A. Adams
1858: 557.
Lima (Ctenoides) tenera. – Dall 1898: 768; Johnson 1934: 26;
McLean 1951: 35, pl. 7, fig. 4.
Lima scabra var./forma/ssp. tenera. – Dall and Simpson 1901: 467;
Arnow et al. 1963: 170 (in part, with ‘white tentacles’); Barrett
and Patterson 1967: 55, text-fig. 3; Abbott 1970: 147; Stanley
1970: 142; Morris 1973: 33, pl. 18, fig. 3; Mpitsos 1973: 371 ff.;
Dance 1974: 240; Zeiller 1974: 55, 2 text-figs; Emerson and
Jacobson 1976: 375, pl. 38, fig. 16; Lozet and Pétron 1977: 124,
fig. 232 (left only); Melvin and Melvin 1980: 85, pl. 52, fig. 7;
Abbott 1986: 212–213, text-fig. 6a; Abbott and Morris 1995: 32,
pl. 26, fig. 7 (but not pl. 4, bottommost figure); Lyons and Quinn
1995: J–11; Porter and Houser 1998: 28.
Lima (Lima) tenera. – Thiele 1918: 9, pl. 1 fig. 5.
Lima inflata ‘Lamarck’ (misidentification; non Limaria inflata
Link, 1807, nec Ostrea inflata Gmelin, 1791). – Smith 1937:
pl. 13, fig. 14 (text corrected in 1945 ed. to Lima tenera).
Lima (Ctenoides) floridana Olsson & Harbison, 1953: 59, pl. 8,
fig. 4; Vokes and Vokes 1984: 38, pl. 37, fig. 5.
Lima (Ctenoides) scabra var./forma/ssp. tenera. – Abbott 1954:
371, fig. 35h; Warmke and Abbott 1961: 171, fig. 34d; Merrill
and Petit 1969: 118; Abbott 1974: 453, pl. 20, fig. 5242a;
Humfrey 1975: 231, pl. 27, fig. 7a; Hemmen and Hemmen 1979:
165; Diaz Merlano and Puyana Hegedus 1994: 62, pl. 10,
fig. 96b; Rios 1994: 243.
Ctenoides glacialis. – Stuardo 1968: 115, pl. 2, fig. 17.
Lima scabra [non C. scaber (Born, 1778)]. – Abbott 1970: 147,
pl. 3b (in part); Abbott 1972: 101, text-fig. (showing white
tentacles); Zeiller 1974: 56, text-fig.; Rehder 1981: fig. 671
only; Kaplan 1982: pl. 19, fig. 7 (showing white tentacles);
Abbott 1984: 51, text-fig. 7; Peeters and Exbrayat 1990: 20
(lower photo only); Sutty 1990: 87, text-fig. (showing white
tentacles); Lipe and Abbott 1991: 72, text fig. 7, 73 (lower photo
only, with white tentacles); Humann 1992: 249 (lower text-fig.
only; showing white tentacles); Snyderman and Wiseman 1996:
100, text-fig.; Shelton 1997: sp. no. 432; Pointier and Lamy
1998: 12, text-fig. (bottom), 187, 3 text-Figs (in part, with white
tentacles); Humann and DeLoach 2002: 326–327, text-fig. (in
part, with white tentacles).
Ctenoides (Ctenoides) floridana. – Vokes 1973: 90–91, pl. 1,
Figs 3–4.
Lima lima [misidentification; non Lima lima (Linné, 1758)]. –
Waller 1976: 8–9; Hamann 1987: 5; Abbott 1989: 41, text-fig.;
Hill and Carmichael 1995: 216, fig.; Williams and Carmichael
1997: 86, fig.
Ctenoides scabra var./forma tenera. – Lindner 1977: 234; Odé
1979: 31–32.
Lima floridana. – Turgeon et al. 1998: 29; ITIS 2002a.
Unidentified. – Williams 1988: 86 (top, as ‘file clam’).
Ctenoides floridana. – Espinosa et al. 1994: 115; Mikkelsen and
Bieler 1998: 223; Redfern 2001: 207, pl. 85, fig. 851; INBio
2001.
Ctenoides scabra glacialis. – Goto and Poppe 1996: 1: 704, 2: 896
(West Indies).
Lima (Limaria) scabra. – Fenner 2002: colour fig. (in part, also
referring to C. scaber).
Ctenoides floridanus. – Mikkelsen and Bieler 2000: 373; García and
Lee 2002: 10.
Ctenoides floridana. – Espinosa and Ortea 2001: 66
Material examined
Type material.Lima mitis: Lamarck (1807: 463) introduced the
name Lima mitis specifically for fig. 653 in Chemnitz’s Conchylien-
Cabinet (1784: pl. 68), an illustration that clearly depicts Ctenoides
mitis as ‘Lima tenera’; the type locality is St Thomas [Virgin Islands],
by original designation. Chemnitz’ specimens of this species have not
been located (Martynov 2002; O. Tendal, in lit., 3 March 2003). Lima
floridana: holotype (27.1 mm), Plio-Pleistocene, Caloosahatchee
Marls, Florida [ANSP (Invertebrate Paleontology) 18214; figured by
Olsson & Harbison, 1953: pl. 8, fig. 4].
Selected other material examined.Bermuda: 1 pair, Challenger
Bank (AMNH 158314). North Carolina: 2 V, off Beaufort Inlet
(NCSM IMS–4420.2). Florida: 1 V, off St Lucie Inlet (FMNH 280496);
1 pair, North Lake Worth Inlet (AMNH 291987); 1 pair, Pompano
Beach (HMNS 13684); 2 pair, Miami (FMNH 26418); 3 pair, Key Bis-
cayne (AMNH 263829); 14 pair, Miami (FMNH 182932); 3 pair, 1 V,
Old Rhodes Key (UMML 28.197); 1 pair, Key Largo Dry Rocks
(HMNS 18322); 5 V, Molasses Reef (FK–202; FMNH 301275); 3 pair,
Tea Table Key (CMNH acc. 14800); 1 alc, Craig Key (FK–640; MZSP
36199); 1 juv pair, 2 V, Coffins Patch (FK–625; AMNH 308074); 7 pair
(live-collected), Grassy Key (AMNH 291983); 2 pair, Key Vaca
(SBMNH 1912); 18 pair, Marathon Key (AMNH 291984); 11 pair, Key
Vaca (AMNH 247503); 13 pair, Marathon, Key Vaca (AMNH 247505);
2 alc, 8 V, Marathon, Key Vaca, bayside (FK–117; FMNH
301271/301272); 9 alc, 1 pair, 1 V, Marathon, Key Vaca, bayside
(FK–118; AMNH 307339); 1 pair, 8 V, Sombrero Reef (FK–662;
FMNH 301284); 2 pair, 13 V, Sombrero Reef (FK–674; FMNH
301285); 9 pair, Pigeon Key (FMNH 182941); 1 alc, Big Pine Key
(HBOM 064:01871); 1 juv pair, Looe Key (AMNH 291985); 5 V, Nine-
foot Shoal (FK–072; FMNH 301267); 2 alc, American Shoals (FK–048;
FMNH 301269); 5 V, American Shoals (FK–358; AMNH 308073);
2 pair, Bahia Honda Key (SBMNH 53711); 4 alc, 3 pair, 7 V, Spanish
Harbor Key (FK–244; AMNH 308072); 2 alc, 1 pair, 3 V, Spanish Har-
bor Key (FK–629; AMNH 305126); 2 pair, Key West (FMNH 182929;
Fig. 22); 3 pair, Dry Tortugas (USNM 458267a); 15 V, Dry Tortugas,
Hospital Key (FK–601; AMNH 308074); 1 pair, 1 V, off Clearwater
(USNM 811252). Alabama: 2 pair (not seen; verified, D. Shelton, per-
sonal communication), off Perdido Pass (Shelton Collection). Louisi-
ana: 2 V juv, off SW Pass (HMNS 5822); 41 V, off Cameron (HMNS
5823). Texas: 1 V, off Freeport (ANSP 410705); 315 V, East Flower Gar-
dens (HMNS 5812); 295 V, West Flower Gardens (HMNS 5816); 1 V,
1 fragment, off Corpus Christi (HMNS 5819). Mexico: 1 V (broken),
Cozumel Island (USNM 736362); 1 V, Yucatan (HMNS 16083); 1 juv
alc, Yucatan (UMML 30.11884). Belize: 1 pair, Carrie Bow Cay
(USNM 771127). Honduras: 1 pair, Islas de la Bahía (HMNS 8219);
1 juv pair (live-collected, plus photo), Isla de Utila (Lloyd Collection).
Panama: 1 pair (live-collected), San Blas Islands (Lloyd Collection).
Bahamas: 1 LV, 2 RV juv, 1 LV juv, Cay Sal Bank (UMML); 1 pair,
Grand Bahama Island (USNM 598309); 1 pair, off North Bimini
(FMNH 57096); 2 alc, Rum Cay (HBOM 064:01725); 1 pair, Abaco

684 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
(AMNH 108240); 2 alc, Andros (AMNH 307194); 1 pair, 1 V, Eleuthera
(UMML 28.494). Cuba: 2 V, Varadero Beach (USNM 458280).
Cayman Islands: 2 pair, Grand Cayman Island (AMNH 85187); 1 alc,
Grand Cayman Island (AMNH 178449). Jamaica: 1 LV, Montego Bay
(AMNH 185354); 1 alc (UMML 30.11888). Hispaniola: 1 V, Haiti
(USNM 440518); 1 V juv, Dominican Republic (AMNH 128880);
1 pair (live-collected), 1 pair, Dominican Republic (UMML 30.11893).
Puerto Rico: 4 pair, S coast (AMNH 291996; Fig. 23); 1 pair, Palamino
Island (AMNH 284484); 1 alc, Aquadilla (AMNH 291995). Virgin
Islands: 1 pair, St Thomas (USNM 103046); 1 V, Nevis (Hewitt Collec-
tion); 1 juv pair, St John (UMML 30.11886); 2 alc, St John (AMNH
141726). Anguilla: 1 V (AMNH 206672). Dominica: 2 pair, Scotts
Head (FMNH 278506). Martinique: 1 V (AMNH 170351). St Vincent:
2 alc, off Kingstown (HBOM 064:02309); 1 pair (AMNH 170481).
Grenadines: 1 V, Carriacou (FMNH 278507). Barbados: 1 pair, 1 V,
Holetown (ANSP 352960). Grenada: 6 V, Levera Beach (FMNH
278508). Colombia: 1 V, off Carrizal (USNM 811245); 2 pair, Old
Providence Island (AMNH 137815); 1 V, Santa Marta (USNM 153489;
Fig. 25). Venezuela: 2 V, off Caracas (USNM 811226); 1 V, Punta de la
Cruz (HMNS 18321). Netherlands Antilles: 2 pair (live-collected),
Aruba (AMNH 247502; Fig. 24); 1 pair (live-collected), Bonaire
(Anderson Collection); 3 V, Curaçao (FMNH 12759).
Diagnosis
Shell white with light brown periostracum, oval, anteriorly
and posteriorly gaping, with c. 90 scaly radial ribs and
transversly grooved interspaces. Prodissoconch 160–170 µm.
Animal with long, white pallial tentacles; mantle, gills, and
smooth pallial veil reddish-orange.
Description
Shell and animal as in Ctenoides scaber, overall slightly
smaller (range 3.3–83.4 mm, mean 36.5 ± 17.7 mm s.d.,
n = 249), sculptured with more numerous, finer radial ribs
(range 59–149, mean = 88.8 ± 12.5 s.d., n = 232);
prodissoconch 160–170 µm in maximum length (AMNH,
n = 2; Fig. 26). Mantle and veil orange to red, tentacles
white or very light orange (Fig. 45); juvenile with gills
orange, tentacles white with red bands (FK–048, c. 20 mm;
similarly described by Stuardo 1968: 103, citing slides from
R. Robertson, ANSP). Eyes as in C. scaber, bright orange-
pink (18 per side in 51.3-mm specimen, FK–118; Fig. 46).
Fine structure of the eyes of this species was described by
Morton (2000, using specimens from the current study,
FK–118); visual physiology and response to predators was
investigated (in this species plus C. scaber) by Mpitsos
(1973).
Distribution
Bermuda, North and South Carolina, south-eastern to north-
western Florida, including the Florida Keys, Alabama,
Louisiana, Texas, Bahamas, Greater and Lesser Antilles,
Caribbean Central and South America (to Venezuela).
Literature records from South Carolina (Merrill and Petit
1969), Tampa Bay (Simpson 1887–1889) and Cedar Keys,
Florida (Dall 1898; Maury 1920), Alabama (Shelton 1997),
Costa Rica (INBio 2001; Espinosa and Ortea 2001), Guade-
loupe (Schramm 1869; Pointier and Lamy 1998) and
Trinidad and Tobago (Stuardo 1968; Work 1969) have not
been verified. Earlier records (e.g. by Thiele 1918) of the
Indian Ocean as part of this species distribution (as Lima
tenera ‘Chemnitz’) probably refer to the Indo-Pacific
species Ctenoides annulatus (Lamarck, 1819) (Stuardo
1968). Also from Miocene Chipola Formation, Florida
(Vokes 1973); Middle Miocene (Virginian), Hillsboro Bay,
western Florida (as ?Lima scabra ‘less spinose variety’;
Heilprin 1887); Miocene shale, Texas (Odé 1979); Pliocene
Caloosahatchee Formation, Florida (Dall 1898; Maury
1920; Olsson and Harbison 1953); Pleistocene, West Indies
(Dall 1898) and northern Gulf of Mexico (Parker 1960);
Pleistocene Cuba (Jaume and Pérez Farfante 1942). Further
information is available as Accessory Material on the
Invertebrate Systematics website.
Habitat and depth
Living individuals are found in habitat similar to that of
Ctenoides scaber, that is, byssally attached to some sort of
rubblely substratum, e.g. under or among rocks, sponges or
coral (AMNH, ex Anderson, ex Lloyd; Warmke and Abbott
1961; Waller 1976; Lawson 1993; Hornsby 2000; Redfern
2001; this study) and especially in crevices of reefs and
ledges (e.g. AMNH, HBOM; ex Lloyd; Odé and Speers
1965; Lipka 1974; Odé 1979; Vokes and Vokes 1984;
Williams 1988; this study). Living specimens from ‘eel
grass’ at Key Biscayne, near Miami (reinterpreted here as
turtlegrass, Thalassia testudinum Koenig; true eelgrass,
Zostera marina Linné, extends only to northern Florida
[Kaplan 1988]), are preserved in the AMNH Collection
(AMNH 263829). Living specimens range from the shallow
subtidal to 53 m (Redfern 2001), with empty-shell or
unspecified records encountered far deeper (525 m; Dall
1886). C. mitis was common among more than 150 species
forming the ‘calcareous bank assemblage’ in the northern
Gulf of Mexico, as delineated by Parker (1960); Lipka
(1974) collected living specimens from one such bank, the
West Flower Gardens, a complex reef habitat at c. 140 m
(with peaks at 20, 55, and 73 m), using the fish-narcotant
rotenone. Like C. scaber in the Florida Keys, C. mitis was
found in Florida Bay at the Stirrup Key and ‘Horseshoe’
sites with artificial rock walls and deeper water to provide
more ocean-like conditions. Woods (1971: 1) reported a
sheltered ‘man-made pool’ on the bayside of Grassy Key
that apparently provided similarly favourable conditions for
C. mitis. Single valves of C. mitis were found in a mangrove
creek on Long Key (FK–656), however, this site is fre-
quented by dive boats returning from the reefs and it is
probable that these specimens were transported from
another location.
Remarks
Although described and discussed as two distinct species by
early authors (e.g. Chemnitz 1784), modern authors have

Western Atlantic Limidae Invertebrate Systematics 685
considered the fine-ribbed Ctenoides mitis as a form, variety,
or subspecies of the more coarsely ribbed C. scaber. Other
workers have figured or described it as Lima lima, have
listed it twice under multiple synonyms (ITIS 2002a, 2002b)
or have listed it as a synonym of Limaria pellucida
(C. B. Adams, 1846) (e.g. Jensen and Harasewych 1986), all
attesting to the taxonomic confusion in this family. Cited
differences (other than the number and strength of radial
ribs) include: C. mitis is smaller than C. scaber (Dall and
Simpson 1901; Nowell-Usticke 1959; Rios 1994; Diaz
Figs 22–26. Ctenoides mitis. 22, External (RV) and internal (LV) views of shell (Key West, Florida
Keys, FMNH 182929, 59.4 mm); 23, additional external views, showing variation in shape, from
Puerto Rico (LV, AMNH 291996, 63.4 mm); 24, Aruba, Netherlands Antilles (LV, AMNH 247502,
46.8 mm); 25, Santa Marta, Colombia (RV, USNM 153489, 43.1 mm), showing slender morphology;
26, prodissoconch (SEM) (LV; Key Vaca, Florida Keys, AMNH 247503). Scale bar = 50 µm (26).

686 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
Merlano and Puyana Hegedus 1994); C. mitis is narrower
relative to height than C. scaber (see Vokes 1973); C. mitis is
is less likely to show concentric growth interruptions on
earliest portion of the shell than C. scaber (see Vokes 1973);
C. mitis is thinner- and more translucent-shelled than
C. scaber (see Chemnitz 1784; Dillwyn 1817); C. mitis is
less common than C. scaber (see Humfrey 1975; Diaz
Merlano and Puyana Hegedus 1994); and C. mitis is West
Indian in distribution while C. scaber is from the eastern
coast of the USA (Goto and Poppe 1996).
None of these claims have been confirmed by this study.
Shell height is similar in range and mean, although
Ctenoides scaber attains larger maximum size; shell length
relative to height overlaps almost completely (Table 2;
Fig. 27). Growth interruptions are noticeable on the valves
of both species with near-equal frequency. Stuardo (1968:
103) noted a difference in the relative ‘size of the adductor
and posterior [pedal] retractor muscles in juveniles’ of
C. scaber and C. mitis; insufficient numbers of living
juveniles were examined during this study to support or
refute this statement. At least in the Florida Keys, the two
species occur in near-equal abundance and often together at
the same depth. This pattern includes co-occurrence on reefs
as well as at two artificially modified rock wall sites in
Florida Bay (where L. caribaea interestingly does not
occur). Sympatry of the two ‘forms’ in several locations was
also noted by Stanley (1970). Documented maximum depths
of living specimens are near-identical (Table 2) although
empty shells of C. mitis have been recorded from substan-
tially deeper localities.
This form is usually called Lima tenera ‘Chemnitz’
Sowerby, 1843, in the western Atlantic literature. The name
Lima tenera was originally proposed by Chemnitz (1784:
345–355, pl. 68, Fig. 653) with good description and
excellent illustration of a specimen from St Thomas;
however, names from Martini-Chemnitz’s non-binominal
work are unavailable (ICZN 1954). Sowerby (1843) made
the name Lima tenera available but gave no locality for the
nominotypical form and cited Pacific locations for unnamed
varieties; he later (1872: sp. 7) gave ‘Philippines, Singapore,
andc.’ as its distribution. Unfortunately, Sowerby’s Lima
tenera is preoccupied by Lima tenera Turton, 1825, now a
synonym of the European Limaria hians (Gmelin, 1791).
Two names have been proposed and discussed for use in
place of the preoccupied Lima tenera ‘Chemnitz’ Sowerby:
(1) Ostrea glacialis Gmelin, 1791. Dillwyn (1817:
271–272) synonymised the nominotypical form of Gmelin’s
Ostrea glacialis under Born’s earlier name Ostrea scabra,
while simultaneously accepting the name Ostrea glacialis
(based on Gmelin’s unnamed variety ‘Ostrea glacialis Var.’)
as a valid name for Lima tenera Chemnitz. Lamarck (1819:
157) used Lima glacialis (Gmelin, 1791) to refer to both
Ctenoides scaber and C. tenera (as glacialis var. ‘b’). In his
description of O. glacialis, Gmelin (1791: 3332) gave a brief
description, referred to several published figures by earlier
authors, and cited ‘Oceano americano’ as type locality.
However, Gmelin’s description clearly referred to a rela-
tively coarsely sculptured shell with 50 (‘quinquaginta’)
ribs, which is matched by the illustrations cited for the
typical form (e.g. Chemnitz 1784: pl. 68, fig. 652). Stuardo’s
(1968: 96 ff.) attempt to solve the tenera-homonymy
problem by restricting Gmelin’s name glacialis to the finely
ribbed tenera of authors is not allowable under the present
Zoological Code (ICZN 1999). Even if it were published,
Stuardo’s (1968: 115) selection of Gmelin’s variety ‘β’
(which referred explicitly to Chemnitz’s fig. 653) is in
violation of ICZN (1999) Art. 72.4.1, which states that
specimens ‘that the author expressly … refers to as distinct
variants’ are not part of the type series of a nominal species-
Table 2. Comparative summary of Ctenoides scaber and C. mitis
C. scaber C. mitis
Mean shell height 53.3 mm (55.1 mm, >20 mm) 36.5 mm (43.8 mm, >20 mm)
Maximum size 107.2 mm 83.4 mm
Radial ribs 28–78 (mean 55.1) 59–149 (mean 88.8)
Prodissoconch 170 µm 160–170 µm
Body colour Reddish-orange Reddish-orange
Pallial tentacles Reddish-orange White or very light orange
Maximum depth 48 m (living), 175 m (empty) 48 m (living), 525 m (empty)
0
10
20
30
40
50
60
70
80
90
020406080100120
Shell height (mm)
Shell length (mm)
Fig. 27. Shell length (=width) v. shell height. Ctenoides scaber
(black circles, n = 200) and C. mitis (open squares, n = 245).

Western Atlantic Limidae Invertebrate Systematics 687
group taxon. O. glacialis is thus here interpreted as a junior
subjective synonym of O. scabra Born, 1778.
(2) Ctenoides floridanus (Olsson & Harbison, 1953).
Vokes (1973) recognised the synonymy of the preoccupied
Lima tenera with a nominal species from the Florida
Pliocene described as Lima (Ctenoides) floridana Olsson &
Harbison, 1953. The latter was introduced as a species
‘similar to Lima tenera in sculpture but differ[ing] by its
narrower form…’ (Olsson and Harbison 1953: 59). The
holotype (pl. 8, fig. 4; ANSP 18214) has a relatively small
shell with 71 ribs. This is within the meristics and measure-
ments of Recent specimens compiled here (Fig. 28); the
shell shape and hinge form are also within the range of
variation illustrated here (Figs 22–25). We therefore agree
with Vokes and some subsequent authors (e.g. Turgeon et al.
1998) in considering Pliocene C. floridanus as conspecific
with the extant form.
However, there is a much earlier and heretofore over-
looked name available for this species. Lamarck (1807: 463)
introduced the name Lima mitis specifically for fig. 653 in
the Conchylien-Cabinet, the illustration that depicts
Chemnitz’s ‘Lima tenera’ from St Thomas; without refer-
ence to Lamarck, Link (1807: 157) subsequently named
Limaria mitis, also basing it on fig. 653. In view of the low
degree of taxonomic stability that has surrounded this
species (there is no available ‘long-accepted name’ to upset,
as addressed in ICZN 1999: Art. 23.2), we follow the
principle of priority by accepting Lima mitis Lamarck, 1807,
as the valid name for this species.
Waller (1976: 8–9, as L. lima, from Bermuda) described
the veil as ‘brilliant red’ with ‘pale tentacles’ and ‘dark red
eyes’ at their bases; the veil of young specimens was lighter
in colour (‘very faint pale pink’). These data agree with our
observations. The behaviour of living captive C. mitis
(including escape response, swimming, crawling, the lack of
a ‘righting’ response when flipped over; also tentacle
morphology) was described by Waller (1976, as L. lima)
based on specimens from Bermuda. There is one record of
an unidentified commensal crab (Pinnotheridae), yellow in
colour, living in the mantle cavity of this species (UMML
30.11887, 17°08′N, 77°35′W, south of Jamaica, 10 fathoms
(18 m), 16.vii.1970, 10-foot otter trawl, coral bottom with
little algae, few sponges).
Ctenoides scaber and C. mitis are nearly completely
overlapping in distribution, from North and South Carolina,
to Florida, Texas, the Bahamas, Greater and Lesser Antilles,
and Caribbean Central and South America to Venezuela.
C. scaber has not been recorded from Bermuda, the north-
ern Gulf of Mexico (Alabama, Louisiana) or from several
Caribbean locations (Dominica, Martinique, St Vincent).
Ctenoides mitis has not been recorded between South
Carolina and south-eastern Florida, nor from Brazil.
The relationship of Ctenoides scaber and C. mitis with
similarly large-shelled Indo-Pacific species, particularly
C. annulatus and C. ales (Finlay, 1926), needs further study.
C. annulatus apparently exists in ‘rough’ and ‘smooth’
forms (Willan 1983), suggestive of the former taxonomic
treatment of C. scaber and C. mitis. Oliver (1992: 83) noted
that C. annulatus has often been considered synonymous
with C. scaber or C. tenera, but that C. scaber ‘has a more
prominent sculpture’; Oliver figured (1992: pl. 14, figs 8a-b)
a 27.2-m shell with c.65 radial ribs, placing it closer in this
regard to C. mitis (fig. 28).
Ctenoides planulatus (Dall)
Flat file clam
(Figs 29–30, Table 3)
Lima tenera var. planulata Dall, 1886: 224. – Thiele 1918: 9.
Ctenoides planulata. – Stuardo 1968 (unpublished dissertation):
119, pl. 3, figs 29–30; Mikkelsen and Bieler 1998: 223.
Ctenoides planulatus. – Mikkelsen and Bieler 2000: 373.
Material examined (total 3 alc, 25 V)
Lectotype (here designated; Table 3). 1 LV, Barbados, BLAKE
Expedition, 1877–1878, 100 fathoms (183 m) (MCZ 7826; Fig. 30);
type locality Barbados, by original designation.
Paralectotypes (Table 3). Nos. 1–3, 1 RV, 2 LV, same data as lecto-
type (MCZ 7826); nos. 4–5, 1 RV, 1 LV, same data as lectotype (USNM
62246; fig. 29).
Other material examined.Florida: 1 RV, 2 LV, off Cape Florida
(USNM 1014021); 1 V, off Key West (USNM 94024). Honduras: 1 alc
(UMML 30.11764); 1 alc (UMML 30.11765). Bahamas: 1 LV, Cay Sal
Bank (UMML 30.11767). St Vincent: 1 alc (UMML 30.11766; includ-
ing one of two largest recorded specimens). Barbados: 1 RV, 1 LV, off
Telegraph Station (USNM 502742); 1 RV, off Telegraph Station
(USNM 1014020); 2 RV, off Lazaretto (USNM 502747); 1 LV, off
Lazaretto (USNM 502750); 5 RV, 2 LV, off Speightstown (HBOM
Fig. 28. Number of ribs v. shell height. Ctenoides scaber (black
circles, n = 184) and C. mitis (open circles, n = 212). The distributions
are significantly different (Mann–Whitney U-Test, P 0.0001).

688 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
064:02175; including one of two largest recorded specimens).
Colombia: 1 LV (UMML 28.2031).
Diagnosis
Shell small (less than 20 mm), white with light brown
periostracum, elongated oval, extremely compressed,
anteriorly gaping, with expanded, dorsally flaring anterior
auricle and much-reduced posterior auricle. Radial ribs very
fine, very numerous (c. 150), tightly packed, scaly to
smooth, divaricating at mid-valve or slightly anteriorly;
interspaces very narrow, punctate. Ventral margin beveled
externally. Prodissoconch 185 µm. Animal (from preserved
soft parts) with long pallial tentacles; pallial veil with
moderately dense, pointed papillae; colour in life unknown.
Description
Shell whitish to light yellow (grey in older specimens),
small (range 9.1–17.5 mm, mean 14.0 ± 2.6 mm s.d., n = 22),
relatively thin-shelled, equivalve, equilateral, elongated oval
in shape. Extremely compressed laterally, very narrowly
gaping anteriorly at enlarged byssal gape (Figs 29–30);
posterior margin not gaping. Ventral margin consistently
with an externally beveled ventral margin; 1–2 earlier
beveled margins evident in some specimens (e.g. MCZ
7826, lectotype, Fig. 30). Shell surface smooth in overall
appearance, especially when worn. Radial ribs very fine,
very numerous (range 109–172, mean 143.1 ± 18.3 s.d.,
n = 14) (Table 3), divaricating at mid-valve or just anterior
to midline, with fine imbricating scales (easily worn off; best
preserved in the freshest specimen available, LV, USNM
1014021, 11.7 mm); interspaces very narrow, in some areas
essentially absent, punctate (reflecting transverse grooves,
as in C. scaber (Fig. 21), but within very narrow inter-
spaces). Anterior auricle larger and dorsally flaring, the
latter with c.15–20 ribs and anterior edge thickened around
byssal gape; posterior auricle smaller, barely demarcated
from main body, with c. 8–13 ribs. Umbones central.
Prodissoconch as in C. scaber, c.185 µm in length (UMML,
n = 3). Hinge line narrow, with a shallow, central, triangular
resilifer. Hinge teeth consisting of small elongated tubercles
at lateral ends of hinge line in LV, articulating with shallow
elongated depressions at lateral ends of hinge line in RV;
anterior tubercle (at dorsal end of flaring byssal gape)
somewhat larger. Inner margin smooth, with slight thicken-
ing just inside the margin. Pallial line simple, entire.
Figs 29–30. Ctenoides planulatus. 29, External view of paralectotype (RV, Barbados, USNM 62246, 15.7 mm); 30, external
and internal views of lectotype (LV, Barbados, MCZ 7826, 16.8 mm).
Table 3. Measurements and valve characteristics of the type material of Ctenoides planulatus
Cat. no. Valve Height (mm) Width (mm) No. of ribs
Lectotype MCZ 7826 LV 16.5 11.2 149
Paralectotype 1 MCZ 7826 RV 12.4 8.1 126
Paralectotype 2 MCZ 7826 LV 16.1 10.1 148
Paralectotype 3 MCZ 7826 LV 14.7 (9.9) (damaged) (encrusted)
Paralectotype 4 USNM 62246 LV 15.8 9.4 155
Paralectotype 5 USNM 62246 RV (15.7) (broken) 9.4 (broken)

Western Atlantic Limidae Invertebrate Systematics 689
Monomyarian, with muscle scars as in C. scaber (Fig. 20).
Periostracum light brown, closely adherent.
Animal (observed from preserved soft parts, UMML)
with Ctenoides-typical pallial tentacles, ctenidia, muscles,
foot, pallial eyes, and wide intestinal loop; exterior surface
of pallial veil covered with moderately dense terminally
pointed papillae; colour in life unknown.
Distribution
South-eastern Florida, Honduras, the Bahamas, St Vincent
(mainly) Barbados, and Atlantic Colombia. No fossil record
known. Further information is available as Accessory
Material on the Invertebrate Systematics website.
Habitat and depth
Living individuals have been collected from 35–40 m
(UMML), associated with coral clumps. Empty shells are
from relatively deep water (40–241 m), in coral, rocks,
and/or sand.
Remarks
Although originally described as an ‘extreme form’ or
variety of Lima tenera (here C. mitis), the shell morphology
of this species differs substantially from that of the latter in
size, byssal gape morphology, inflation, and sculpture. Dall
(1886) noted that ‘intermediates occur between this and
tenera,’ however, no such forms have been recognised
during this study. The pallial veil with terminally pointed
papillae is characteristic of this species.
Stuardo (1968) studied only the ‘type’ lot (MCZ 7826).
He gave the dimensions of the ‘holotype’ as 16.4 × 10.2 mm;
we have chosen the same valve here as lectotype, as the
largest valve and that in the best condition within the
syntypic series. See remarks under Ctenoides vokesi,
sp. nov. (below), for comparison with other members of
Stuardo’s ‘C. planulata group.’
Ctenoides sanctipauli Stuardo
Brazil file clam
(Figs 31–33)
Ctenoides sanctipauli Stuardo, 1982: 146–148, fig. 1. – Stuardo
1968 (unpublished dissertation): 117, pl. 1, fig. 7; Mikkelsen
and Bieler 2000: 373.
Material examined (total 4 pairs, 43 V, + fragments)
Holotype. 1 LV, Rocedos de São Paulo (St Paul’s Rocks), SW
Saddle, 60–80 fathoms (110–146 m), 13.iv.1963, Chain 35, sta. 15 [MCZ
261389; fig. 32; figured by Stuardo 1968: pl. I, fig. 7 (as 32.4 mm);
Stuardo 1982: fig. 1 (left)]. The type locality is Rocedos de São Paulo (St
Paul’s Rocks), north-east of Brazil, by original designation.
Paratypes. 5 RV, 6 LV, 5 fragments, same data as holotype (MCZ
316560, ex MCZ 261389).
Other material examined.South Carolina: 2 juv LV, 1 juv RV,
3 fragments, off Charleston (USNM 875154); 1 RV, 1 LV, off Charles-
ton (USNM 875100); 1 juv RV, 6 juv LV, off Charleston (USNM
875045). Florida: 1 pair with traces of dried tissue, 2 RV, 1 LV, off
Egmont Key (AMNH 99694; including largest recorded specimen);
1 pair with intact ligament, off Sarasota (AMNH 161513); 1 pair with
intact ligament, Marathon, Key Vaca (BMSM 2232; Fig. 33); 1 pair
with traces of dried tissue, Sand Key Reef [MCZ 316561 (ex USNM
458136); Fig. 31; listed in original description, but not as type mate-
rial]; 1 RV, off Sand Key (USNM 458282); 1 LV, off Dry Tortugas
(FMNH 197565); 5 RV, 6 LV, 1 fragment, off Dry Tortugas (AMNH
195668). St Lucia: 1 RV (UMML 30.11883). Nicaragua: 1 LV, off
Huani (USNM 1014022). Netherlands Antilles: 1 RV, 1 LV, off
Curaçao (USNM 811243).
Diagnosis
Shell whitish, roundly ovate, only narrowly gaping anteri-
orly. Sculpture very smooth, with c. 100 flattened radial ribs,
with low, blunt terminal ends adorned only by minute lateral
spines; concentric periodic growth stoppages, producing
ringed effect. Interspaces very narrow, smooth. Prodisso-
conch 240 µm. Animal unknown.
Description
Shell whitish to light yellow, c. 25 mm (range 5.7–42.6 mm,
mean 25.67 ± 11.44 mm s.d., n = 40), relatively thin-shelled,
equivalve, equilateral, rounded oval in shape (Figs 31–32).
Moderately compressed laterally, very narrowly gaping
anteriorly (byssal gape), with only slightly thickened
recurved margins; posterior margin not gaping. Ventral
margin smooth, thin. Shell surface smooth in appearance.
Radial ribs numerous (range 62–165, mean 113.26 ± 29.25
s.d., n = 31), flattened, divaricating at mid-valve, formed of
low overlapping plates terminating in blunt ends with
minute spines at one side (pointing away from the valve
midline), creating appearance of minute ‘notches’ along
side of each rib; interspaces very narrow, smooth (Fig. 33).
Small anterior auricle with anterior edge slightly thickened
around byssal gape. Posterior auricle larger, but barely
demarcated from body, with 8–10 ribs. Umbones central.
Hinge line narrow, with a shallow, central, triangular
resilifer. Hinge teeth consisting of small elongated tubercles
at lateral ends of hinge line in LV, articulating with shallow
elongated depressions at lateral ends of hinge line in RV;
anterior tubercle (at dorsal end of byssal gape) somewhat
larger. Inner margin smooth. Pallial line simple, entire.
Monomyarian, with muscle scars as in C. scaber (Fig. 20).
Prodissoconch as in C. scaber, 240 µm in maximum length
(BMSM, n = 1). Periostracum thin, light tan to golden
yellowish. Animal unknown.
Distribution
South Carolina, Gulf of Mexico off western and south-
western Florida, including Florida Keys and Dry Tortugas;
St Lucia; Nicaragua; Netherlands Antilles; Brazil. Literature
records from off Cuba (Stuardo, 1968, 1982) have not been
verified. No fossil record known. Further information is
available as Accessory Material on the Invertebrate System-
atics website.

690 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
Habitat and depth
Live-collected specimens (i.e. shells containing dried tissue)
are from 183–366 m (and see remarks below); empty shells
are from 91–274 m. In his unpublished description of this
form, Stuardo (1968: 117) gave its depth range as 80–287
fathoms (146–525 m); this was emended to 60–127 fathoms
(110–232 m) in publication (Stuardo 1982). Stuardo (1968)
placed C. sanctipauli in a species group with three other
species, all of which were considered adapted to soft
bottoms. The only habitat recorded here for live-collected
specimens is ‘among coral blocks at low tide’ (MCZ
316561).
Figs 31–33. Ctenoides sanctipauli. 31, External view of Floridian specimen (RV, Sand Key Reef,
Florida Keys, MCZ 316561 (33.0 mm); 32, external and internal views of holotype (LV, Rocedos de São
Paulo, MCZ 261389, 32.3 mm); 33, detail of sculpture (SEM) showing scaly ribs, smooth interspaces,
and mid-valve divarication (Marathon, Florida Keys, BMSM 2232); scale bar = 500 µm.

Western Atlantic Limidae Invertebrate Systematics 691
Remarks
Stuardo (1968) placed Ctenoides sanctipauli in a species
group with C. philippinarum Masahito & Habe, 1978
(Philippines), C. symmetrica (Barnard, 1964) (South
Africa), and C. concentrica (Sowerby, 1888) (Hong Kong).
Although most depth records for Ctenoides sanctipauli
are greater than 100 m, two Florida Keys specimens (Sand
Key Reef; ‘shore,’ MCZ 316561; bayside of Marathon, Key
Vaca, unspecified depth, BMSM 2232) are from uncharac-
teristically shallow locations. Both of these specimens are
double valves presumably recently-alive when collected
(evidenced by soft tissue or intact ligament, respectively),
and their occurrence in these localities remains unexplained.
The remaining evidence is very strong that this is, in
general, a deep-water species.
Ctenoides miamiensis, sp. nov.
Miami file clam
(Fig. 34, Table 4)
Ctenoides new species (manuscript name) Stuardo 1968
(unpublished dissertation): 119, pl. 1, Fig. 12.
Material examined (total 5 pair, 2 V)
Holotype. 1 pair, Miami Beach Causeway [Dade County], 1940,
A. Koto (FMNH 182931; Fig. 34); type locality Miami, Dade County,
Florida.
Paratypes. Nos 1–2, 2 RV, Dominican Republic, Bahía de
Samaná, NE coast of Hispaniola, 19°10.2′N, 69°27.3′W to 19°10.2′N,
69°28.1′W, 16.5 fathoms (30.2 m), ‘contained a large number of forms,
including many molluscs,’ 3-foot dredge, 16.ii.1933, Johnson-
Smithsonian Deep-Sea Expedition, R/V CAROLINE sta. 56 (USNM
429390; figured by Stuardo 1968 [unpublished dissertation]: pl. 1,
fig. 12); nos. 3–4, 2 pair (1 with dried anatomy), Florida Keys, ‘Tortu-
gaes’ (Dry Tortugas), C. T. Simpson (UMML 30.11763); nos. 5–6, 2
pair (both with dried anatomy), Gulf of Mexico, Florida Keys, N of
Marquesas Keys, 24°25′N, 82°26′W, 501 m, 02.ii.1968, R/V JOHN
ELLIOTT PILLSBURY sta. P–967 (UMML 30.11762).
Other material examined. None.
Diagnosis
Shell small (c. 10 mm), inequilateral (obliquely oval) in
outline, with anterior margin concave and posterior margin
convex. Radial ribs coarse (c. 50), closely spaced, scaly, with
interspaces transversely grooved. Periostracum light brown.
Prodissoconch 170–185 µm. Animal (from dried soft parts)
with long pallial tentacles; colour in life unknown.
Description
Shell white, small (range 4.8–13.6 mm, mean 9.4 ± 2.6 mm
s.d., n = 7), relatively thin-shelled, equivalve, inequilateral,
obliquely oval in shape (Fig. 34). Moderately compressed
laterally, very narrowly gaping anteriorly (byssal gape), with
slightly thickened recurved margins; posterior margin not
gaping. Ventral margin smooth. Scaly radial ribs similar to
those of C. scaber (Fig. 21), relatively coarse (range 44–55,
mean 49.4 ± 3.5 s.d., n = 7) (Table 4), divaricating at mid-
valve, plus somewhat oblique transverse grooves in inter-
spaces. Anterior auricle concave, compressed, thickened
around byssal gape. Posterior auricle larger, expanded,
barely demarcated, with 5–6 ribs. Hinge line narrow,
umbones anterior of midline. Resilifer shallow, obliquely
triangular; resilium similarly shaped, golden brown in
colour. Hinge teeth consisting of relatively large elongated
tubercles at lateral ends of hinge line in LV, articulating with
shallow elongated depressions at ends of hinge line in RV.
Pallial line simple, entire. Monomyarian, with muscle scars
as in C. scaber (Fig. 20). Prodissoconch as in C. scaber,
Fig. 34. Ctenoides miamiensis, sp. nov., external (RV) and internal (LV) views of holotype (Miami Beach
Causeway, Florida, FMNH 182931, 10.4 mm).

692 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
c.170–185 µm in maximum length (FMNH, USNM,
UMML, n = 4). Periostracum light tan.
Animal (observed from dried soft parts, UMML
30.11762) with long pallial tentacles and Ctenoides-typical
ctenidia, muscles, and foot; presence of eyes and papillation
of pallial veil unclear; colour in life unknown.
Distribution
South-eastern Florida, the westernmost Florida Keys and
Dry Tortugas, and Hispaniola. No fossil record known.
Further information is available as Accessory Material on
the Invertebrate Systematics website.
Habitat and depth
Live collected specimens (UMML) are from 501 m deep in
the Gulf of Mexico. Other records with recorded depth
information are from beach (holotype) to 30.2 m depth
(paratypes 1–2). Nothing is known about its preferred habitat.
Remarks
Stuardo (1968, unpublished) recognised this species as new
based only on the specimen here representing Paratype 1
(USNM 429390, in part) but did not formally introduce a
name. Ctenoides miamiensis is the coarse-ribbed counter-
part of C. obliquus (see below) in much the same relation-
ship as C. mitis with C. scaber. Stuardo (1968) placed this
form in a species group with three other strongly oblique
taxa: a South African species later named C. barnardi
Kilburn, 1998 (= Lima divaricata Barnard, 1964, non
Dujardin, 1837), a new (but never formally named) Indo-
Pacific species, and the Atlantic species here described as
C. obliquus. A 20.8-mm LV of C. barnardi figured by
Kilburn (1998: fig. 60) has ~86 radial ribs.
Etymology
Named for the type locality, Miami, Florida.
Ctenoides obliquus, sp. nov.
Oblique file clam
(Figs 35–36, Table 5)
Ctenoides new species (manuscript name) Stuardo 1968
(unpublished dissertation): 118, pl. 1, fig. 14.
Material examined (total 25 alc, 12 pair, 70 V)
Holotype. 1 pair, with soft body in alcohol, Brazil, Guiana Basin,
‘ca.’ São Sebastiao de Vicosa [State of Para], ‘ca.’ [no degrees on
label]°53′N, 46°19′W, 40-foot flat trawl, 37–38 fathoms (68–70 m),
15 May 1975, R/V OREGON II cruise 58, sta. BBC–1629, Collette
(USNM 767413; Fig. 35); type locality Guiana Basin, off state of Pará,
northern Brazil.
Paratypes. No. 1, 1 pair with ligament and dried tissue remnant,
Nicaragua, 150 miles E of Puerto Cabezas, 14°05′N, 81°21′W, 100
fathoms (183 m), 08.vi.1964, R/V OREGON sta. 4928 (USNM
811229); no. 2, 1 pair, Nicaragua, 85 miles ESE of Prinzapolca,
13°09′N, 82°15′W, 80 fathoms (146 m), 21.xi.1968, R/V OREGON II
sta. 10202 (USNM 810481; Fig. 36); no. 3, 1 pair with dried tissue,
Panama, off Colon (‘near Aspinwall’), 09°32.0′N, 79°54.4′W, 34 fath-
oms (62 m), broken shell, United States Fish Commission, ALBA-
TROSS sta. 2146, large beam-trawl (USNM 94070); no. 4, 6, 1 RV, 1
LV, Bahamas, Andros Island, off Coakley Town, Fresh Ck, 400 fathoms
(732 m), vi.1950, MOTHER GOOSE II, J. Armstrong (AMNH
232643); no. 5, 1 pair with ligament and dried tissue remnant, Guyana,
07°45′N, 57°34′W, 30–35 fathoms (55–64 m), R/V OREGON sta. 2248
(USNM 636784; figured by Stuardo 1968 [unpublished dissertation]:
pl. 1, fig. 14); nos. 7–9 and 11, 2 RV, 2 LV, Cuba, off Havana, 80 fathoms
(146 m), 1877–1878, BLAKE Expedition, Sigsbee (MCZ 7824;
Fig. 36); no. 10, 1 RV, Florida, Martin County, c. 4 miles S of St Lucie
Inlet, 27°07′N, 80°07′W, 11 m, scuba (sediment sample), 12.ix.1985,
R. Bieler (FMNH 280496); no. 12, 1 LV, Grand Bahama Island, Lucaya,
26°29.45′N, 78°37.15′W, c. 300 m, x.1984, J. Worsfold (ANSP
372595); nos. 13–15, 3 alc, Venezuela, NE of Caracas, 11°00′N,
65°55W, 112 m, 22.vii.1968, R/V JOHN ELLIOTT PILLSBURY sta.
P–736 (UMML 30.11752); nos. 16–17, 2 alc, Grenada, 12°23.55′N,
61°21.6′W, 20–137 fathoms (37–250 m), 03.vii.1969, 5-foot Blake
trawl, R/V JOHN ELLIOTT PILLSBURY sta. P–857, steep slope with
sponges (UMML 30.11740).
Other material examined.Florida: 1 LV, off Cape Florida
(USNM 1014018). Gulf of Mexico: 1 RV, 1 LV, between Mississippi
Delta and Cedar Keys (USNM 94002). Mexico: 1 LV, Yucatan (UMML
30.11758). Nicaragua: 1 pair with ligament, off Huani (USNM
811250). Panama: 3 pair (UMML 28.2137); 1 RV (UMML 28.1820).
Bahamas: 1 RV, 3 LV, Cay Sal Bank (UMML 30.11761); 2 RV, Cay Sal
Bank (UMML 30.11759); 1 RV, 4 LV, Cay Sal Bank (UMML
30.11760); 1 alc, Bimini (UMML 30.11750); 1 pair, off Great Inagua
Island (USNM 811237). Turks and Caicos Islands: 1 pair (UMML
30.11742). Cuba: 1 RV (UMML 30.11757); 1 LV, off Havana (USNM
193564); 2 RV, 2 LV, off Havana (USNM 62244). Hispaniola: 1 alc, off
NE coast Dominican Republic (UMML 30.11746). Puerto Rico: 2 RV,
4 LV, off N coast (USNM 430268); 3 RV, 1 LV (USNM 430074); 2 RV,
3 LV, off N coast (USNM 429171). Martinique: 7 alc, 2 RV, Case Pilote
(UMML 30.11743). Anguilla: 1 juv alc (UMML 30.11749). Guade-
loupe: 1 RV (UMML 30.11755). Dominica: 1 juv alc, 1 LV (UMML
30.11741). St Lucia: 1 RV (UMML 30.11754). St Vincent: 1 alc
(UMML 30.11748); 1 RV, 1 LV (UMML 30.11756); 3 alc (UMML
30.11747). Barbados: 4 RV, 4 LV, off Speightstown (HBOM
Table 4. Measurements and valve characteristics of the type material of Ctenoides miamiensis, sp. nov.
Cat. no. Valve Height (mm) Width (mm) No. of ribs
Holotype FMNH 182931 pair 10.4 9.3 48
Paratype 1 USNM 429390 RV 10.0 8.7 51
Paratype 2 USNM 429390 RV 4.8 4.4 47
Paratype 3 UMML 30.11763 pair 8.2 7.1 50
Paratype 4 UMML 30.11763 pair 10.0 8.3 51
Paratype 5 UMML 30.11762 pair 9.1 8.2 44
Paratype 6 UMML 30.11762 pair 13.6 11.8 55

Western Atlantic Limidae Invertebrate Systematics 693
064:02765); 1 LV (USNM 95913); 3 RV, 4 LV, off Telegraph Station
(USNM 502744). Colombia: 1 alc, off Peninsula de la Guajira
(UMML 30.11745); 1 RV, 1 LV, off Peninsula de la Guajira (UMML
30.11753; including largest recorded specimen). Venezuela: 1 pair with
dried tissue remnant, off Amuay (USNM 810480). Netherlands
Antilles: 3 alc (UMML 30.11744); 1 pair with ligament and dried tis-
sue remnant, off Curaçao (USNM 811244).
Diagnosis
Shell small to medium-sized (to 40 mm), inequilateral
(obliquely oval) in outline, with anterior margin concave and
posterior margin convex. Radial ribs fine (c. 100), scaly,
closely spaced; interspaces transversely grooved. Perio-
stracum light brownish yellow. Prodissoconch 185 µm.
Animal (from preserved soft parts) with long pallial tenta-
cles; pallial veil with dense terminally rounded papillae,
expanded visceral mass with wide intestinal loop; colour in
life unknown.
Description
Shell white, small to medium (range 4.1–40.0 mm, mean
15.0 ± 8.0 mm s.d., n = 79), relatively thin-shelled,
equivalve, inequilateral, obliquely oval in shape
(Figs 35–36). Moderately compressed laterally, very nar-
rowly gaping anteriorly (byssal gape), with slightly thick-
ened recurved margins; posterior margin not gaping. Ventral
margin smooth. Radial ribs fine, numerous (range 84–114,
mean 99.8 ± 6.9 s.d., n = 30) (Table 5), scaly, divaricating at
mid-valve; interspaces transversely grooved (as in C. scaber,
Fig. 21). Anterior auricle concave, compressed, thickened
around byssal gape. Posterior auricle larger, expanded,
Figs 35–36. Ctenoides obliquus, sp. nov. 35, External (RV) and internal (LV) views of holotype (Guiana
Basin, USNM 767413, 19.2 mm); 36, external (RV) and internal (LV) views of paratype 2 (off Caribbean
Nicaragua, USNM 810481, 23.3 mm).

694 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
barely demarcated, with 10–12 radial ribs. Hinge line
narrow, umbones anterior of midline. Resilifer shallow,
obliquely triangular; resilium similarly shaped, golden
brown in colour. Hinge teeth consisting of relatively large
elongated tubercles at lateral ends of hinge line in LV,
articulating with shallow elongated depressions at ends of
hinge line in RV. Pallial line simple, entire. Monomyarian,
with muscle scars as in C. scaber (Fig. 20). Prodissoconch
as in C. scaber, c. 185 µm in maximum length (USNM,
n = 5).
Animal (observed from preserved soft parts, UMML)
with Ctenoides-typical pallial tentacles, ctenidia, muscles,
foot, pallial eyes, and wide intestinal loop; exterior surface
of pallial veil covered with dense, terminally rounded
papillae; colour in life unknown.
Distribution
South-eastern Florida, north-eastern Gulf of Mexico, Baha-
mas, Greater and Lesser Antilles, Central America and
northern South America. Stuardo (1968) stated a range as
far south as off the Abrolhos Islands, Brazil, which has not
been verified here. No fossil record known. Further informa-
tion is available as Accessory Material on the Invertebrate
Systematics website.
Habitat and depth
Live-collected from 1–201 m; empty shells from 11–1335
m. Records for habitats of live-collected material include
among sponges (UMML), coral rubble (UMML), and
broken shell (USNM).
Remarks
Ctenoides obliquus is the fine-ribbed counterpart of
C. miamiensis; see remarks under C. miamiensis (above). It
shares with C. planulatus the character of a papillose pallial
veil (smooth in C. scaber and C. mitis; unclear in
C. miamiensis), but the papillae in this species are more
dense than in C. planulatus and are uniformly terminally
rounded.
Etymology
From obliquus, L. adj., meaning slanting.
Ctenoides vokesi, sp. nov.
Vokes file clam
(Figs 37–38, Table 6)
Material examined (total 7 V)
Holotype. 1 RV (partially encrusted, with small hole), Barbados,
off Telegraph Sta., 30–70 fathoms (55–128 m), rocks and sand, S.U.I.
Exp. 1918, Barbados sta. 79, JB Henderson Jr. (USNM 1014019;
Fig. 37); type locality Barbados.
Paratypes. No. 1, 1 LV (partially encrusted with worm tubes,
bryozoans), Little Abaco Island, off NE end, 27°08′N, 77°52′W,
150–165 fathoms (273–302 m), 25.x.1961, R/V SILVER BAY sta.
3474, National Marine Fisheries Service (USNM 811256; Fig. 38); no.
2, 1 RV (white, worn, with very small drill hole), Antigua, Falmouth
Harbor, 3–6 fathoms (5–11 m), grassy bottom, S.U.I. Exp. 1918, Anti-
gua Sta. 104, J. B. Henderson, Jr. (USNM 502740); no. 3, 1 RV (heavily
encrusted with worm tubes, bryozoans, small oyster), Barbados, off
Telegraph Station, 40–75 fathoms (73–137 m), coarse sand, S.U.I. Exp.
1918, Barbados sta. 80, J. B. Henderson Jr. (USNM 502745); no. 4,
1 LV (chipped lower edge, partially encrusted with worm tubes, bryo-
zoans), Florida, off Cape Florida [S tip of Key Biscayne, Dade County],
25°47.0′N, 80°05.0′W, 85 fathoms (155 m), grey sand/foraminiferans,
deep sea dredge, 09.iv.1886, United States Fish Commission, ALBA-
TROSS sta. 2646 (USNM 93409); no. 5, 1 RV fragment, Bahamas,
Andros Island, Fresh Ck, off Coakley Town, 400 fathoms (731 m),
vi.1950, MOTHER GOOSE II, J. Armstrong (AMNH 134089); no. 6,
1 LV, Bahamas, Cay Sal Bank, 24°05′N, 80°19′W, 22–132 fathoms
Table 5. Measurements and valve characteristics of the type material of Ctenoides obliquus, sp. nov.
Cat. No. Valve Height (mm) Width (mm) No. of ribs
Holotype USNM 767413 alc 19.2 14.4 103
Paratype 1 USNM 811229 pair 24.2 19.8 96
Paratype 2 USNM 810481 pair 23.3 22.4 112
Paratype 3 USNM 94070 pair 14.0 11.5 100
Paratype 4 AMNH 232643 RV 13.1 10.7 99
Paratype 5 USNM 636784 pair 11.3 9.5 95
Paratype 6 AMNH 232643 LV 15.1 11.8 103
Paratype 7 MCZ 7824 RV 8.9 7.7 94
Paratype 8 MCZ 7824 LV 8.5 6.9 103
Paratype 9 MCZ 7824 LV 8.0 7.1 99
Paratype 10 FMNH 280496 RV 6.1 5.6 67
Paratype 11 MCZ 7824 RV 5.4 4.7 98
Paratype 12 ANSP 372595 LV 4.1 3.8 89
Paratype 13 UMML 30.11752 alc 18.3 14.6 102
Paratype 14 UMML 30.11752 alc 21.3 16.2 114
Paratype 15 UMML 30.11752 alc 23.2 17.6 100
Paratype 16 UMML 30.11740 alc 9.7 7.5 81
Paratype 17 UMML 30.11740 alc 22.8 15.6 97

Western Atlantic Limidae Invertebrate Systematics 695
(40–241 m), 05.iii.1968, 10-foot otter trawl, R/V GERDA sta. 986
(UMML 30.11768).
Other material examined. None.
Diagnosis
Shell moderately large (to 60 mm), elongated oval, com-
pressed, anteriorly gaping with expanded, dorsally flaring
anterior auricle and smaller posterior auricle. Radial ribs
fine (c. 90), scaly, divaricating at mid-valve or slightly
posteriorly; interspaces transversely grooved. Prodissoconch
and animal unknown.
Description
Shell whitish to tan (grey in older specimens), moderately
large (range 30.1–60.1 mm, mean 47.4 ± 11.4 mm s.d.,
n = 5), relatively thin-shelled, equivalve, equilateral, elon-
gated oval in shape (Figs 37–38). Moderately compressed
laterally, very narrowly gaping anteriorly (byssal gape);
posterior margin not gaping. Radial ribs fine, numerous
(range 78–107, mean 95.3 ± 10.7 s.d., n = 6) (Table 6),
divaricating at mid-valve or just posterior to midline,
minutely scaly, closely spaced, with transverse grooves in
narrow interspaces (as in C. scaber, Fig. 21). Anterior
auricle large and flaring noticeably dorsally, the latter with
c. 20–24 ribs and anterior edge thickened around byssal
gape; posterior auricle smaller, weakly demarcated, with
c. 6–8 ribs. Umbones central. Hinge line narrow, with
shallow, central, triangular resilifer. Hinge teeth consisting
of small elongated tubercles at lateral ends of hinge line in
LV, articulating with shallow elongated depressions at ends
of hinge line in RV; anterior tubercle (at dorsal end of flaring
byssal gape) somewhat larger. Inner margin smooth, with
slight thickening just inside the margin. Pallial line simple,
entire. Monomyarian, with muscle scars as in C. scaber
(Fig. 20). Periostracum, prodissoconch, and animal unknown.
Distribution
South-eastern Florida, Bahamas, and the Lesser Antilles. No
fossil record known. Further information is available as
Accessory Material on the Invertebrate Systematics website.
Habitat and depth
Living individuals are unknown. One valve is from shallow
water (5.5–11.0 m, seagrass, Antigua, PARATYPE 2,
Figs 37–38. Ctenoides vokesi, sp. nov. 37, External and internal views of holotype (RV, Barbados, USNM 1014019,
60.1 mm); 38, internal view of paratype 1 (LV, Little Abaco Island, Bahamas, USNM 811256, 54.3 mm).
Table 6. Measurements and valve characteristics of the type material of Ctenoides vokesi, sp. nov.
Cat. No. Valve Height (mm) Width (mm) No. of ribs
Holotype USNM ex 502744 RV 60.1 40.0 107
Paratype 1 USNM 811256 LV 54.3 37.6 93
Paratype 2 USNM 502740 RV 43.9 29.7 78
Paratype 3 USNM 502745 RV 48.5 31.2 98
Paratype 4 USNM 93409 LV 30.1 20.9 98
Paratype 5 AMNH 134089 RV (26.7) (damaged) (18.5) (damaged) (98)
Paratype 6 UMML 30.11768 LV 62.7 36.9 (105+) (damaged)

696 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
USNM 502740), but it is extremely beachworn. All other
specimens are from sand or rocky bottom, in relatively deep
water (40–732 m).
Remarks
Stuardo (1968, unpublished) placed three species in his
‘Ctenoides planulata group’: the relatively large C. ales, and
a smaller new species (never formally described), both from
the Indo-Pacific, and the relatively small C. planulatus from
the western Atlantic. The species group was characterised by
elongated, compressed shells, with fine, smooth sculpture,
and a flaring byssal gape (Figs 29–30) called ‘pouting’ by
Dall (1886: 224). C. vokesi adds a second large-shelled form
to the C. planulatus group which now includes one large and
one small species each from the Indo-Pacific and western
Atlantic.
This new species closely resembles Ctenoides planulatus
in general appearance, but attains much larger size while
having substantially fewer ribs on the main body of the shell.
The ribs of C. planulatus are also unique, being demonstra-
bly flattened and laterally notched, unlike those of C. vokesi,
C. scaber, and C. mitis. The zone of divarication is
consistently different between C. planulatus and C. vokesi,
being anterior of the midline in the former and posterior of
the midline in the latter. The posterior auricle is much more
clearly delineated in C. vokesi, being almost undifferentiated
in C. planulatus. Paratype 6 (UMML 30.11768) is abnor-
mally narrow, probably due to habitat-induced growth
constriction (see Discussion), and is broken at the posterior
auricle; however, the sculpture and enlargement of the
anterior ear confirm its identity. All species of Ctenoides
studied herein show submarginal thickening on the inside of
the valves (C. scaber and C. mitis show this only at large
sizes); only C. planulatus shows external beveling of the
ventral margin as well. Indo-Pacific C. ales (n = 1, Marshall
Islands, AMNH 277143, 37.8 mm, 91 ribs), although not
extensively surveyed, agrees with C. vokesi in overall
morphology, though its whitish shell is suffused with yellow,
especially along the internal marginal thickening; its close-
set ribs are minutely scaled (contrary to Stuardo’s descrip-
tion) and similar in all respects to those of C. vokesi.
Etymology
Named for the late Harold E. Vokes in recognition of his
extensive work on the taxonomy of fossil and Recent limids
and other marine bivalves.
Discussion
Shell characters
Shell characters are important taxonomically within Limi-
dae. The generic distinction of Lima v. Ctenoides at the
conchological level focuses on three features: the anterior
shell slope, the radial ribs, and the periostracum. Lima has a
strongly oblique, non-gaping anterior shell slope, non-
divaricating radial ribs (not increasing in number with
size/age), and non-persistent periostracum. Ctenoides has a
evenly oval anterior slope with a prominently thickened
byssal gape, divaricating radial ribs that increase in number
with size/age, and brownish adherent periostracum.
Although the rib scales of limids are all generally described
as ‘imbricating’ (i.e. formed of overlapping plates), this
feature is not true upon close examination of Lima s. s., in
which the broad, blunt rib scales are attached to or emerge
fingernail-like from a more-or-less solid rib surface. In
Ctenoides, the rib scales are the pointed ends of the
imbricating plates forming each rib. Although superficially
different in C. sanctipauli, the ribs are likewise formed of
overlapping scales, albeit each ending low and bluntly with
only a minute marginal spine.
At the species level within each genus, distinguishing
shell characters include relative size, shell outline, inter-
space sculpture, and the relative number of radial ribs. Rib
number has been widely used as a specific character in a
variety of limid genera. The fundamental importance of rib
number in distinguishing Lima lima and L. caribaea has
been discussed above. The species pairs Ctenoides
scaber/mitis and C. miamiensis/obliquus are also readily
separated on the basis of the number of radial ribs on the
shell (Table 2). Stuardo’s (1968: 114) postulated diagnostic
difference in absolute rib number in C. scaber and C. mitis
(‘less than 60’ in the former; ‘over 80’ in the latter) is,
however, unusable because the number is dependent upon
size (e.g. increasing by divarication with shell height) and
there is considerable overlap in range (see Table 2; Fig. 28).
Nevertheless, when coupled with shell height and especially
with tentacle colour in the living animal (see following),
relative number of ribs is unambiguous in distinguishing
between these two species. Rib number relative to body size
has also been discussed here in distinguishing C. vokesi and
C. planulatus (see Remarks under C. vokesi), with the
former attaining a much larger size but never as many ribs.
Rib number in bivalves of the family Pectinidae has been
declared to be under genetic control by Kraeuter et al.
(1984, although refuted in part by Marelli et al. 1997).
Shell shape in Ctenoides species can be influenced by
habitat. Both C. scaber and C. mitis inhabit crevices or reef-
holes, which they seldom leave, and this occasionally results
in an unusually narrow shell shape (Jacobson and Hernan-
dez 1973; Emerson and Jacobson 1976). A survey of
collections and the literature produced slender specimens of
three species that probably resulted from the space limita-
tions of such a restricting habitat (C. scaber from FK–069,
FK–092, FK–121, AMNH 701142 (Fig. 19), BMSM 223,
DMNH 61988 and 7654, FMNH 278509 (Fig. 18), HMNS
18221; Sowerby 1843: fig. 4, as ‘var.’; Sowerby 1872: pl. 2,
fig. 8b; Smith 1940: text-fig. 1316 (repeated 1945: pl. 10,
fig. 1); Burgess 1985: 98, text-fig.; C. mitis from FK–072,

Western Atlantic Limidae Invertebrate Systematics 697
FK–202, FK–358, FK–629, FK–662, DMNH 29251,
USNM 153489 (Fig. 25); Vokes 1973: pl. 1, fig. 3a-b;
C. vokesi from UMML 30.11768 (PARATYPE 6)). Occa-
sionally, a specimen shows expansion of growth (from
slender to more typical oval shape; Fig. 19), suggesting
relocation from a restrictive to a more open habitat. This
same phenomenon has been noted in Lima lima (fide Poppe
and Goto 1993), although specimens of Lima spp. thus
affected were not seen during this study.
Soft-anatomical characters
Relatively few species of Lima s. s. and Ctenoides have been
described anatomically. To date, five species of Lima (lima,
marioni, tetrica, tomlini, vulgaris) and five species of
Figs 39–40. Diagrammatic anatomy of 39, Lima and 40, Ctenoides, each in right lateral
view (am, adductor muscle; an, anal papilla; by, byssus; ct, ctenidium; ft, foot; in, intestine;
lp, labial palp; prm, pedal retractor muscle; pt, pallial tentacles; pv, pallial veil; st, stomach;
vrm, visceral retractor muscle).

698 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
Ctenoides (annulatus, barnardi, japonicus, scaber, one
undescribed) have at least some detailed anatomical data
available.
Pelseneer (1911) provided ‘the most complete account of
the anatomy of limas’ (Harry 1982: 43), discussing a wide
range of anatomical features in 18 nominal species, all as
members of Lima s. l. Most of Pelseneer’s comments are
now attributed to species of Acesta, Limaria or Limatula
(some difficulties arise because Pelseneer did not include
authorities with his taxonomic names, and one nomen
nudum appears included; Stuardo 1968), however two
species of Lima (L. lata = L. marioni, L. lima, L. squamosa
= L. lima) and two species of Ctenoides [L. dunkeri =
C. japonicus (Dunker, 1877); L. tenera = C. annulatus
(Lamarck, 1819); revised taxonomy as per Stuardo 1968]
were included.
Stuardo’s unpublished dissertation (1968) is the only
other general morphological treatment of Limidae species.
He provided anatomical illustrations for 17 species of
Limidae (discussed comparatively but not individually
described), including Lima vulgaris, L. tomlini, Ctenoides
scaber, one new species of Ctenoides, C. barnardi,
C. japonicus, and C. annulatus.
Other works covering limid morphology are restricted to
single organ systems. Hesse (1900) provided a detailed
study of the pallial eyes of Mediterranean Lima lima (as
L. squamosa); Dakin (1928: 362) described the eyes of this
same species as ‘little pits without a lens’ and noted their
simplicity compared with those of pectinids. Finally, Morton
(2000) produced a detailed histological study of the eyes of
Ctenoides mitis based on material from the present study
(see also Figs 42, 46). Concentration of the ganglia of the
nervous system in L. lima, near the centre of the visceral
mass, was illustrated by Pelseneer (1907 (as L. squamosa),
1911, 1931). The synaptorhabdic gill structure of Limidae
species, based in part on L. lima (as L. squamosa) and
L. tetrica (as the unattributed ‘L. californica’) was included
in the extensive comparative work on gill morphology by
Ridewood (1903: 215–217).
The morphology of the hypertrophied lips of members of
Limidae (Fig. 47) was also discussed very early (e.g. by
Pelseneer (1906), including Lima lima (as L. squamosa)).
Bernard (1972), Gilmour (1974), and Morton (1979) each
discussed the wide range in lip complexity, from the
simplest form in Limatula spp. to the very complex, fused
configuration in Limaria spp. Differing from these extremes,
those of L. lima, L. tetrica (see Pelseneer 1906; Bernard
1972), L. vulgaris (as L. lima; Morton 1979: fig. 7A), and
Ctenoides scaber (see Gilmour 1974) apparently form with
Acesta an intermediate morpological group, called the ‘free
limid lip type’ by Bernard (1972). Morton (1979) also
provided a detailed description of the ciliary currents over
the lips, as well as the mantle, ctenidia, labial palps, and
visceral mass of L. vulgaris.
The pedal (mucus and byssal) glands of Lima lima (as
L. squamosa) were described by Barrois (1885). Byssal
gland morphology and the byssal fibres of the same species
were also examined by Seydel (1909), who commented on
reversal of the relative position of the foot. In 1990, Gilmour
further discussed the phenomenon of foot reversal in
Limoidea, wherein the foot and byssal apparatus are
oriented anteriorly and provided additional anatomical
information for Lima lima and Ctenoides scaber.
Lacaze-Duthiers (1854) described the reproductive sys-
tem of Lima lima (as L. squamosa) as dioecious, also
including size and form of the eggs and spermatozoa. Little
else is known within the family that might be compared with
these data, excepting Lodeiros and Himmelman’s (1999)
populational study that determined Ctenoides scaber to be a
protandric hermaphrodite.
Stomach morphology for Limidae is routinely cited as
Type IV of Purchon (1957, 1987), however the latter work is
based solely on ‘Lima’ hians and L. fragilis (Gmelin, 1791),
both of which are now members of Limaria. Original gross
Figs 41–42. Anatomical features of Ctenoides mitis (SEM)
(FK–118, AMNH 307339, 56.7 mm). 41, Foot tip; 42, pallial tentacles,
showing basal widening and longitudinal grooves (by, byssal threads;
ey, eye). Scale bars = 500 µm (42), 1.5 mm (41).

Western Atlantic Limidae Invertebrate Systematics 699
dissection during this study of the stomachs of Lima
caribaea (FK–115) and Ctenoides scaber (FK–047) found
no discernible differences from that presented by Purchon
(1957: fig. 10) for Limaria fragilis, extending the validity of
this stomach type within the family.
Most soft-anatomical features of limids are characteristic
of genera. Stuardo (1968: 47) saw a morphological differ-
ence in the lips of Lima and Ctenoides, postulating that
‘those of Ctenoides are somewhat less evolved [than those
of Lima and Acesta], indicating that they originated from
infolds of the labial flaps and part of the lips, and not only as
outgrowths of the internal walls of the lips …’. Two other
genus-level characters are added by this study. (1) The
intestinal loop is widely 8-shaped within the ventral visceral
mass in Ctenoides spp. (fig. 40, in; see also Stuardo 1968:
49, fig. 4, C. scaber), but is narrowly appressed between the
adductor and pedal retractor muscles in Lima spp. (Fig. 39,
in; see also Pelseneer 1911: pl. 10, fig. 5, reproduced in
1931: fig. 4, L. lima). A wide intestinal loop is apparently
also present in members of Limaria (see Pelseneer 1911:
pl. 10, fig. 6; von Studnitz 1931: Figs 1, 13; both L. inflata
Link, 1807) and Limatula (see Stuardo 1968: fig. 36,
L. hodgsoni (E. A. Smith, 1907)). (2) Gross morphology of
the pallial tentacles is distinctly different in the two genera
studied here, i.e. cylindrical and ungrooved in Lima or
basally widened with a strong longitudinal groove in
Ctenoides (Fig. 42). This character difference has not been
previously discussed in the literature, but has been con-
firmed during this study in six species (L. caribaea,
C. scaber, C. mitis, C. planulatus, C. obliquus, from
material cited herein; L. vulgaris, Western Australia,
FMNH 201229). Griffin (1911: 328) described the tenta-
cular structure of an unidentified species of ‘Lima’ (whose
swimming behaviour and autotomising tentacles, however,
suggest a Limaria) with ‘a narrow longitudinal groove … on
the outer surface of the tentacle’; Gilmour (1963a, b)
described or figured those of Acesta excavata, Limaria
hians, and L. loscombei (Sowerby, 1820) as cylindrical.
Basal widening by itself could be an artefact of preser-
vation, however it can be noted that Stuardo (1968) figured
widened tentacle bases in several species of Ctenoides,
Lima, Acesta, Limea, and Limatula; he figured distinctly
cylindrical tentacle bases in species of Limaria. Suggestion
of a longitudinal groove was illustrated for Acesta ango-
lensis (W. Adam & Knudsen, 1955) and Limea sarsi Lovén,
1846 (Stuardo 1968: Figs 29, 41), but was not discussed in
either case. Family-wide investigation of tentacle morpho-
logy is warranted.
Figs 43–47. 43, Living Lima caribaea (FK–115, AMNH 299636, 41.3 mm, 37.8 mm width); 44, living Ctenoides scaber
(FK–115, FMNH 301263, 58.1 mm, 40.1 mm width); 45, living Ctenoides mitis (FK–117, FMNH 301272, 53.5 mm, 41.1 mm
width); 46, detail of Ctenoides mitis dissection, showing base of tentacles with two eyes (bracketed) (FK–118, AMNH 307339,
51.3 mm); 47, detail of Ctenoides mitis dissection, showing lips (FK–118, AMNH 307339, 51.3 mm) (lp, lips; mo, mouth).
Scale bars = c. 0.5 mm (45); c. 2.0 mm (46).

700 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
Few consistent anatomical differences were identified at
the species level in the present study. Observed in the wet-
preserved material available, the external surfaces of the
pallial veils of Ctenoides planulatus and C. obliquus are
distinctly papillose (with pointed papillae in the former,
rounded papillae in the latter), while those of Lima caribaea,
C. scaber, and C. mitis are smooth to finely granulate with
transverse folds suggestive of muscle bands. The presence
or absence of papillae cannot be discerned with certainty in
dried anatomical material, and furthermore, has not yet been
observed in living specimens. Further study is needed.
Tentacle length and colour and body colouration are
manifestly useful traits of limids for species-level distinc-
tion. This study has placed high confidence in the consist-
ency of tentacle/body colouration in Florida Keys Ctenoides
spp. (red-red in C. scaber and red-white in C. mitis).
Nevertheless, interspecific variation in tentacle colour
(unrelated to taxonomic ‘lumping’ or confusion) is evident
in the literature on these two species. For instance, Redfern
(2001: pl. 124, fig. 852C, as C. scabra) clearly illustrated a
living specimen from the Bahamas with the coarse shell ribs
indicative of C. scaber and the white tentacles of C. mitis.
Such apparent exceptions suggest that populations in areas
outside the Florida Keys deserve similarly close scrutiny.
Identification of juveniles based on colouration poses its
own problems: those of both species possess light orange
bodies and white and red-banded tentacles. Personal obser-
vations in Western Australia have confirmed that soft-body
colouration can vary within populations or ontogenetically
in other limids; L. nimbifer was overall tan with an yellow-
orange veil but larger individuals had additional red pig-
ment, producing an overall reddish purple effect; in Limaria
sp., the smallest specimen was completely white (except for
a black digestive gland), while larger individuals were light
orange, slightly darker on the foot, longer tentacles, and
gills, and with a dark orange gonad.
Key to the western Atlantic species
of Lima and Ctenoides
The following artificial key to the western Atlantic species of Lima and
Ctenoides, as a result of this study, shows that the shell remains the
strongest source of taxonomic characters at the species level. Soft
anatomical characters are mainly useful in distinguishing genera, or in
some cases, as corroborating evidence for species identified using shell
characters.
1. Shell ribs non-divaricating, solid, with attached fingernail-like
spines (Fig. 6); anterior slope strongly oblique; periostracum
non-persistent; pallial tentacles uniformly cylindrical, not
grooved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Lima 2
Shell ribs divaricating, formed of overlapping plates ending in
pointed scales (Fig. 21); anterior slope rounded with
thickened byssal gape; periostracum persistent, light brown;
pallial tentacles basally widened, longitudinally grooved
(Fig. 42). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Ctenoides 3
2(1). Shell obliquely triangular; radial ribs 22–34 (mean 27);
interspaces smooth (Fig. 6); prodissoconch 195 µm . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . L. caribaea
Shell rounded triangular; radial ribs 31–37 (mean 33);
interspaces with transverse scratches (Fig. 14);
prodissoconch 285–300 µm . . . . . . . . . . . . . . . . . L. marioni
3(1). Rib spines prominent, terminally pointed; interspaces
transversely grooved . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Rib spines minute, placed laterally at terminal edges of rib plates
(Fig. 31); interspaces smooth; shell rounded oval; radial ribs
62–165 (mean 113); prodissoconch 240 µm . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C. sanctipauli
4(3). Shell equilateral, elongated oval in outline . . . . . . . . . . . . . . . 5
Shell inequilateral, obliquely oval in outline. . . . . . . . . . . . . . 6
5(4). Shell moderately inflated; prodissoconch c. 170 µm. . . . . . . . 7
Shell strongly compressed. . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
6(4). Radial ribs 47–51 (mean 49); prodissoconch 170–185 µm
(pallial veil unknown) . . . . . . . . . . . C. miamiensis, sp. nov.
Radial ribs 84–114 (mean 100); prodissoconch 185 µm; pallial
veil papillose . . . . . . . . . . . . . . . . . . . . C. obliquus, sp. nov.
7(5). Radial ribs 28–78 (mean 55); pallial tentacles red . . . C. scaber
Radial ribs 59–149 (mean 89); pallial tentacles white . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C. mitis
8(5). Adult size relatively small (9–17 mm); ventral margin beveled
externally; radial ribs 109–172 (mean 143); prodissoconch
185 µm; pallial veil papillose. . . . . . . . . . . . . .C. planulatus
Adult size relatively large (30–60 mm); ventral margin not
beveled externally; radial ribs 78–107 (mean 95)
(prodissoconch and pallial veil unknown) . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . C. vokesi, sp. nov.
Phylogenetic relationships
A phylogenetic analysis of Limidae based on shell and
anatomical characters has not been published and is not
within the scope of this geographically and taxonomically
restricted paper. However, identification of anatomical char-
acters that allow taxonomic separation at various levels was
one of our original objectives, and several features distin-
guishing Lima and Ctenoides spp. have been identified here
based on literature or original data.
Phylogenetic relationships within Limidae have been
previously implied though the discussion of species- or
genus-groups by previous authors. Yonge (1953) distin-
guished two groups of ‘Lima’ based on the habit of byssal
attachment (e.g. Lima, Ctenoides, with better developed
pedal retractors, and single mouth opening) or not (=nest
builders, e.g. Limaria, with weaker pedal retractors and two
lateral mouth openings leading to oesophagus). Later
Stuardo (1968: 51 ff.) recognised, as noted above, that
Ctenoides, Acesta, and Lima share a comparable state of lip
complexity relative to other limid genera. He further noted a
total of 18 characters distinguishing two large groups of
limid genera, Ctenoides–Lima–Acesta–Divarilima and
Limaria–Limatula–Limea. These features cover a wide
range of organ systems, associated with the byssus, pallial
veil, foot, the various muscles, eyes, mantle diverticulum,
the heart ventricles, the nerve ganglia, labial palps, the
intestinal loop, abdominal sense organs, and an enigmatic
(sensory?) ‘membranous process.’

Western Atlantic Limidae Invertebrate Systematics 701
Table 7. Comparative characteristics in tentacles and body colour of worldwide Limidae species
Species Tentacles Body colour Sources/Locality
Lima caribaea Short, white to reddish
purple
Orange to reddish purple Simpson 1887–1889: 70; Humann 1992: 248–249, text-fig.;
Humann and DeLoach 2002: 326–327, text-fig.; this study (all
western Atlantic)
Lima fugitae Oyama, 1943 Short, white Yellow de Suduiraut 2002 (Balicasag Island, Philippines)
Lima nimbifer Short, white Veil yellow-orange to purple, foot
and gills white
R. Bieler, pers. obs. (Western Australia)
Lima vulgaris Short, purple turning to
white
Purple turning to white Morton 1979 (as L. lima); Beesley et al. 1998: pl. 11, Fig. 4 (as
L. lima) (Indo-Pacific)
Lima sp. Short, whitish Dark red veil and ?gills Sharabati 1981: 94, colour photo (Arabian peninsula)
Lima sp. Short, cream-white White veil, dark pink gills Clayton 1974: 45, text-fig. [as Lima (=Limaria) hians]
(Mediterranean and north-eastern Atlantic)
Ctenoides ales Long, red Red-streaked veil with white
bioluminescent margin; red-
orange internally
Okutani, 1994: pl. 1; Okubo et al. 1997 (both Japan); photo
purchased from Neville Coleman (Uepi Island, Solomon
Islands)
Ctenoides mitis Long, white [uncommonly
light orange]
Red Simpson 1887–1889: 70; Abbott 1970: 147, pl. 3b (in part, Lima
scabra); Abbott 1972: 101, text-fig. (as Lima scabra); Lipka
1974: 160; Zeiller 1974: 55, text-fig.; Lutz 1986: cover;
Williams 1988: 86 (top, as ‘file clam’); Abbott 1989: 41, text-
fig. (as L. lima); Sutty 1990: 87 (as L. scabra); Hill and
Carmichael 1995: 216, fig. (as L. lima); Pointier and Lamy
1998: 12, text-fig., 187, 3 text-Figs (as L. scabra); Hornsby
2000: 26, text-fig. (as rough file clam); Humann and DeLoach
2002: 326–327, text-fig. (in part, as L. scabra); Fenner 2002:
fig. [as Lima (Limaria) scabra]; this study (all western
Atlantic)
Ctenoides philippinarum Long, white Yellow with light orange mottling de Suduiraut 2002 (Balicasag Island, Philippines)
Ctenoides scaber Long, red/orange Bright orange/red Simpson 1887–1889: 70; Abbott 1954: pl. 35o; 1962b: 6 (as
‘lima clam’); Abbott 1970: 147, pl. 3b (in part, Lima scabra);
Emerson and Jacobson 1976: 375; Voss 1976: pl. 1 (as L.
scabra); Voss 1980: cover and pl. opp. p. 96; Salvini-Plawen
and Abbott 1984: 160 (as ‘file shell’); Haywood and Wells
1989: 164, text-fig. (as L. scabra); Gordon 1990: 120; Lawson
1993: cover; Pointier and Lamy 1998: cover + 175, text-fig. (as
Lima); Porter and Houser 1998: 28, text-fig. (as Lima);
Humann and DeLoach 2002: 326–327, text-fig. (in part);
Invertebrate Biology 2002 [cover of 121(4), as L. scabra]; this
study (all western Atlantic)
Limaria pacifica
(d’Orbigny, 1846)
Long, orange Orange Hickman and Finet 1999: 20.
Limaria basilanica
(Adams & Reeve, 1850)
Long, white White de Suduiraut 2002 (Balicasag Island, Philippines)
Limaria fragilis Long, red-orange (or
banded red/cream)
Red-orange Coleman 1981: fig. 418; Johnson 1982: 103, top; Kay and
Schoenberg-Dole 1991: fig. 135; Great Barrier Reef Marine
Park Authority 1995 (as Lima lima); de Suduiraut 2002; Fenner
2002 (Pacific)
Limaria hians Long, translucent, light
orange
Light orange/white veil, orange-
pink body
Sowerby 1854: pl. 12, Fig. 1 (as Lima tenera [Turton]); Gilmour
1963a, 1963b; Bouchet et al. 1979: 115 (as Lima hians); Canet
2002: fig. (all eastern Atlantic)
Limaria hirasei Pilsbry, 1901 Long, red to red-orange Red Griffin 1911 (as Lima sp.); de Suduiraut 2002 (as cf. hirasei)
(Philippine Islands)
Limaria orientalis
(A. Adams & Reeve, 1848)
Long red tentacles Red Fenner 2002: fig. (No. Sulawesi, Indonesia)
Limaria pellucida Long, white White with yellow or orange gills Pointier and Lamy 1998: 188, text-fig.; Humann and DeLoach
2002: 326–327, text-fig.; Mikkelsen and Bieler, unpub.
(western Atlantic)
Limaria tuberculata
(Olivi, 1792)
Long, translucent with
brown longitudinal stripe
[some all brown or with
tan base]
Gills/veil suffused with brown Clayton 1974: 45, text-fig. (as Lima rotundata Sowerby, 1843)
(Indian Ocean)
Limaria tuberculata
(Olivi, 1792)
Long, white Pink-orange interior Salvini-Plawen and Abbott in Grzimek et al. 1984: 141, Fig. 4
(colour drawing, as Lima tuberculata; Europe)
Limatula hodgsoni Short, white White Brueggeman 2003: fig. (Antarctica)
Limatula strangei Long, light orange Light orange Bennett 1987: 316, centre; Beesley et al. 1998: pl. 11, fig. 3;
photos purchased from Neville Coleman (Australia)

702 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
Although less definite, annulation of the pallial tentacles
also suggests generic groupings of limids and might ulti-
mately provide another character of phylogenetic value.
Annulations are distinctly present in Limaria spp. (Gilmour
1963a, 1963b; Stuardo 1968; Waller 1976; Morton 1979).
Gilmour (1963a, 1963b, 1967) showed these annulations to
be external rings of gland cells in L. hians, and noted how
readily such tentacles autotomise when the animal is
disturbed (also noted by the present authors in Florida Keys
L. pellucida) and postulated that they assist in burrowing,
swimming, and defensive behaviours. Similar ringed
tentacle morphology is suggested in Stuardo’s illustrations
of the anatomy of Limatula and Limea spp., although the
author stated that annulations were ‘restricted only to the
species of Limaria s. s.’ (Stuardo 1968: 28, figs 30, 37–39,
41, 43). Annulations are clearly present in Limatula strangei
(Sowerby, 1872) (Beesley et al. 1998: pl. 11, fig. 3).
Papillose but non-annulated tentacles are evident in species
of Lima (this study) and Ctenoides (Stuardo 1968; Waller
1976; this study); Morton’s (1979: fig. 3) drawing of the
tentacles of Lima vulgaris (as L. lima) as identically
‘segmented’ to those of Limaria spp. is probably in error.
Homologies of the annulations of Limaria, the papillae of
Ctenoides and Lima, and the as-yet-unstudied ‘rings’ of
Limatula and Limea require further investigation.
A cursory search of literature and web images of living
worldwide Limidae suggests some level of phylogenetic
signal in characters of tentacle length and, to some extent,
body colouration. Tentacle length is usually consistent at the
genus-level: long in Ctenoides and Limaria and short in
Lima (Table 7), although this trait appears to be variable in
Limatula (short in L. hodgsoni, long in L. strangei). The
tentacles of Lima spp. and Limatula hodgsoni are usually all
white or cream-white, although the darker body colouration
of some species sometimes extends over the tentacles (e.g.
Morton 1979; Humann 1992). Poppe and Goto (1993) stated
that the animal of most Limidae species is bright orange or
red, and other available data agree in that most recorded
species are pigmented with some hue of purple, red, orange,
yellow, or brown (Table 7). Lin and Pompa (1977) found an
unusual (for invertebrates and for bivalves) carotenoid
metabolism in C. scaber, with echinenone metabolised from
β-carotene comprising 62% of the red pigment.
Although the body of anatomical evidence, published and
unpublished, suggests at least two clades within Limidae
(Ctenoides–Lima–Acesta–Divarilima and Limaria–Lima-
tula–Limea), robust phylogenetic testing awaits a worldwide
comparative morphological study. Such a study must
include conchological, anatomical and molecular characters
across the full range of extant genera.
Acknowledgments
We dedicate this paper to the late Harold E. Vokes who early
recognised the taxonomic problems in fossil and Recent
western Atlantic limids (Vokes 1973) but whose conclusions
have gone largely unacknowledged. For assistance with
collecting in the Florida Keys we thank Roberto Cipriani
(then FMNH and University of Chicago; now Universidad
Simón Bolívar, Caracas, Venezuela), Timothy Collins and
Timothy Rawlings (both Florida International University,
Hollywood, Florida), Homer and Ann Rhode (Ramrod Key,
Florida), and the captains and crews of R/V Bellows
(Florida Institute of Oceanography, St Petersburg, Florida),
R/V Eugenie Clark (Mote Marine Laboratory, Sarasota,
Florida), and R/V Coral Reef II (Shedd Aquarium, Chi-
cago). Collecting in the Florida Keys National Marine
Sanctuary was performed under FKNMS Permits 080-98,
2000-036, 2002-078, and 2002-079; in the vicinity of
Pigeon Key (on National Register of Historic Places) under
the auspices of the Pigeon Key Foundation; in the Dry
Tortugas National Park, under collecting permits
DRTO-19970030 and 2002-SCI-0005; in Long Key State
Park (Long Key, Florida Keys) under Florida Department of
Environmental Protection permit 5-02-43; in Key West
National Wildlife Refuge (near Sand Key, Florida Keys)
under United States Fish and Wildlife Service permit
41580-01-07; and additional collecting under Florida Fish
and Wildlife Conservation Commission permit 99S-024 to
affiliates of The Bailey-Matthews Shell Museum (Sanibel,
Florida) and permit 01S-056 (as well as annual permits for
prior years of this study) to affiliates of the Smithsonian
Marine Station (Ft. Pierce, Florida; logistic support by Mary
E. Rice and staff is much appreciated). For access to
collections and specimen data/loans, we thank Miroslav
Harasewych and Raye Germon (USNM), Nancy Voss
(UMML), Debra Krumm and Laura Siemon (HBOM), José
Leal (BMSM), Arthur Bogan (NCSM), Charlotte Lloyd
(Jacksonville Beach, Florida), Susan Hewitt (AMNH),
Roland Anderson (Seattle Aquarium, Washington), Gary
Rosenberg and Paul Callomon (ANSP), Kenneth Boss and
Adam Baldinger (MCZ), Kathie Way (BMNH), Philippe
Bouchet and Virginie Heros (MNHN), Ole Tendal, Zoolo-
gisk Museum, University of Copenhagen), Gonzalo Giribet
(Harvard University), and Douglas Shelton (Mobile, Ala-
bama). Norman Newell (AMNH) notably brought Stuardo’s
(1968) unpublished dissertation on Limidae to our attention.
Roberto Cipriani assisted with statistical analyses; Gary
Rosenberg (ANSP) and Fabrizio Scarabino (Museo
Nacional de Historia Natural, Montevideo, Uruguay) helped
with obtaining additional literature; Philippe Bouchet
(MNHN) offered advice on interpreting the ICZN and
taxonomic authorship; Richard Petit and Alan Kabat, as so
often before, helped us find and disentangle obscure litera-
ture references; Angela Klaus (AMNH) assisted with scan-
ning electron microscopy; Charissa Baker (New York City)
produced the shell drawing in Fig. 20; Steve Thurston
(AMNH) computer-rendered the anatomical drawings
(Figs 38–39) and assisted with digital imagery. Neville

Western Atlantic Limidae Invertebrate Systematics 703
Coleman (Queensland, Australia) made available photo-
graphs of worldwide living Limidae. Assistance with speci-
men light photography was provided by Roy Larimer
(Microptics, Inc.), David Grimaldi, Tam Nguyen and Portia
Rawlings (AMNH). Two anonymous reviewers improved the
readability of the manuscript. This research, in part, was
supported by NSF-PEET DEB-9978119 and Comer Science
and Education Foundation grants to the authors. Additional
fieldwork support from the AMNH Proctor-Old-Sage Mala-
cology Fund, Bertha LeBus Charitable Trust, Field
Museum’s Womens Board, and the FMNH Zoology Depart-
ment’s Marshall Field Fund is also gratefully acknowledged.
This is Smithsonian Marine Station Contribution no. 574.
References
Abbott, R. T. (1954). ‘American Seashells.’ (D. Van Nostrand: New
York, USA.)
Abbott, R. T. (1962a). ‘Sea Shells of the World.’ (Golden Press: New
York, USA.)
Abbott, R. T. (1962b). ‘Shells.’ (Nelson Doubleday: Garden City, New
York, USA.)
Abbott, R. T. (1968). ‘Seashells of North America.’ (Golden Press:
New York, USA.)
Abbott, R. T. (1970). ‘How to Know the American Marine Shells,’ rev.
ed. (New American Library: Bergenfield, NJ, USA.)
Abbott, R. T. (1972). ‘Kingdom of the Seashell.’ (Crown Publishers:
New York, USA.)
Abbott, R. T. (1974). ‘American Seashells: the Marine Mollusca of the
Atlantic and Pacific Coasts of North America,’ 2nd ed. (Van
Nostrand Reinhold: New York, USA.)
Abbott, R. T. (1984). ‘Collectible Florida Shells.’ (American Malacol-
ogists: Melbourne, FL, USA.)
Abbott, R. T. (1986). ‘A Guide to Field Identification: Seashells of
North America,’ rev. ed. (Golden Press: New York, USA.)
Abbott, R. T. (1989). ‘Shells.’ (Portland House: New York, USA.)
Abbott, R. T., and Morris, P. A. (1995). ‘A Field Guide to Shells:
Atlantic and Gulf Coasts and the West Indies,’ 4th ed. Peterson
Field Guide no. 3. (Houghton Mifflinn: Boston, MA, USA.)
Adams, H., and Adams, A. (1853–1858). ‘The Genera of Recent
Mollusca; arranged according to their organization.’ Volume II.
(John van Voorst: London.) [Family Radulidae, pp. 556–559,
published in part 33, January 1858.]
Agassiz, L. (1834). ‘Recherches sur les Poissons Fossiles. 4.
Cténoïdes.’ (Petitpierre: Neuchatel, Switzerland.)
Agassiz, L. (1848). ‘Nomenclatoris zoologici index universalis, contin-
ens nomina systematica classium, ordinum, familiarum et generum
animalium omnium, tam viventium quam fossilium, secundum
ordinem alphabeticum unicum disposita, adjectis homonymiis
plantarum.’ (Jent et Gassmann: Soloduri [Soleure, Switzerland].)
Aguayo, C. G. (1943). Centenario de los “Moluscos” de d’Orbigny en
la obra de la Sagra. Revista de la Sociedad Malacólogica “Carlos
de la Torre” 1(1), 37–40.
Aguayo, C. G., and Jaume, M. L. (1948). Pelecypoda – Limidae.
Catalogo Moluscos de Cuba 430.
Aldrich, B., and Snyder, E. (1936). ‘Florida Sea Shells.’ (Houghton
Mifflin: Boston, MA, USA.)
Andrews, J. (1981). ‘Texas Shells.’ (University of Texas Press: Austin,
TX, USA.)
Andrews, J. (1994). ‘A Field Guide to Shells of the Florida Coast.’
(Gulf Publishing Company: Houston, TX, USA.)
Anton, H. E. (1838). ‘Verzeichniss der Conchylien welche sich in der
Sammlung von Hermann Eduard Anton befinden.’ (E. Anton:
Halle, Germany.)
Arnow, L., F. St. Clair, and T. Arnow. (1963). The Mollusca of a
lagoonal area at Playa de Vega Baja, Puerto Rico. Caribbean
Journal of Science 3(2–3), 163–172.
Baily, J. L., Jr. (1950). Locomotion in Lima. The Nautilus 63(4),
112–113.
Barfield, B. (1990). Cognate bivalve species of the western Atlantic and
eastern Pacific Oceans. American Conchologist 18(2), 20–22.
Barrett, R., and Patterson, D. eds. (1967). ‘Shells and Shelling.’ (Post
Publications: Miami, FL, USA.)
Barrois, T. (1885). ‘Les Glandes du Pied et les Pores Aquifères chez les
Lamellibranches.’ (L. Danel: Lille, France.)
Bartsch, P. (1937). An ecological cross-section of the lower part of
Florida based largely upon its molluscan fauna. In ‘Report of the
Committee on Paleontology 1936–1937’, pp. 11–25. (National
Research Council, Division of Geology and Geography: Washing-
ton, DC, USA.)
Beesley, P. L., Ross, G. J. B., and Wells, A. (eds.). (1998). ‘Mollusca:
The Southern Synthesis.’ Fauna of Australia, Volume 5, Part A.
(CSIRO Publishing: Melbourne, Australia.)
Bennett, I. (1987). ‘W. J. Dakin’s Classic Study – Australian Sea-
shores.’ (Angus and Robertson Publishers: Sydney, Australia.)
Bernard, F. R. (1972). Occurrence and function of lip hypertrophy in
the Anisomyaria (Mollusca, Bivalvia). Canadian Journal of
Zoology 50, 53–57.
Bieler, R., and Mikkelsen, P. M. (1998). Ammonicera in Florida: notes
on the smallest living gastropod in the United States and taxonomic
comments on other species of Omalogyridae (Heterobranchia). The
Nautilus 111(1), 1–12.
Bieler, R., Ball, A. D., and Mikkelsen, P. M. (1998). Marine Valvato-
idea – comments on anatomy and systematics with description of a
new species from Florida (Heterobranchia: Cornirostridae). Malac-
ologia 40(1), 305–320.
Bohnsack, J. A., Harper, D. E., and McClellan, D. B. (1994). Fisheries
trends from Monroe County, Florida. Bulletin of Marine Science
54, 982–1018.
Born, I. (1778). ‘Index rerum naturalium Musei Caesarei Vindobo-
nensis. Pars I.ma Testacea. – Verzeichniß der natürlichen Selten-
heiten des k. k. Naturalien-Kabinets zu Wien.’ Erster Theil.
(Schalthiere: Vienna, Austria.)
Born, I. (1780). ‘Testacea Musei Caesarei Vindobonensis quae jussu
Mariae Theresiae Augustae disposuit et descripsit.’ (Vienna,
Austria.)
Bosc, L. A. G. (1802). ‘Histoire Naturelle de Coquilles, Contenant leur
Description, les Moeurs des Animaux qui les Habitent et leurs
Usages.’ Volume 2. (Deterville: Paris, France.)
Bouchet, P., Danrigal, F., and Huyghens, C. (1979). ‘Sea Shells of
Western Europe.’ (American Malacologists: Melbourne, FL, USA.)
Brayfield, L., and Brayfield, W. (1993). ‘A Guide for Identifying
Florida Fossil Shells and Other Invertebrates,’ 3rd ed. (Florida
Paleontological Society: Gainesville, FL, USA.)
Bronn, H. G. (1848). ‘Index Palaeontologicus oder Übersicht der bis
jetzt bekannten fossilen Organismen. Erste Abtheilung. A. Nomen-
clator palaeontologicus, in alphabetischer Ordnung. Erste Hälfte.
A-M.’ (E. Schweizerbart: Stuttgart, Germany.)
Brooks, J. (1968). Keys after “Abby”. Seafari 10(7), 8.
Brown, R. W. (1940). Fossil pearls from the Colorado group of western
Kansas. Journal. Washington Academy of Sciences, Washington,
D. C. 39(9), 365–374.
Brueggeman, P. (2003 [undated]). ‘Underwater Field Guide to Ross
Island & McMurdo Sound, Antarctica.’ http://scilib.ucsd.
edu/sio/nsf/fguide/mollusca20.html [last accessed 06 January
2003]. (University of California: San Diego, CA, USA.)

704 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
Bruguière, J. G. (1792). ‘Encyclopédie Méthodique, Histoire Naturelle
des Vers.’ Vol. 1. Part 2. pp. 345–758. (Panckoucke: Paris, France.)
Bruguière, J. G. (1797). [Plates 190–286. ] In ‘Tableu Encyclopédique
et Méthodique des Trois Règnes de la Nature. Vers, Coquilles,
Mollusques et Polypiers’. (Agasse: Paris, France.) Plates 190–286.
[For collation, see Evenhuis and Petit 2003.]
Bucquoy, E., Dautzenberg, P., and Dollfus, G. F. (1888). ‘Les Mollus-
ques Marins du Roussillon. Tome II – Fascicule II, Pelecypoda
(Fascicule 15); Familles: Anomiidae, Spondylidae, Radulidae;
Genres: Anomia, Spondylus, Radula.’ (J. -B. Baillière et Fils,
P. Dautzenberg: Paris, France.)
Burgess, C. M. (1985). ‘Cowries of the World.’ (Gordon Verhoef,
Seacomber Publications: Cape Town, South Africa.)
Butler, A. J. (1998). Order Limoida. In ‘Mollusca: The Southern
Synthesis’. Fauna of Australia, Volume 5, Part A. (Eds P. L. Beesley,
G. J. B. Ross and A. Wells.) pp. 267–268. (CSIRO Publishing:
Melbourne, Australia.)
Calkins, W. W. (1878). Catalogue of the marine shells of Florida, with
notes and descriptions of several new species. Proceedings of the
Davenport Academy of Natural Sciences 2, 232–252.
Canet, M. M. (2002 [ver. 06 August 2002]). ‘Animales Marinos.’
http://www.animalesmarinos.com/peinecillo.htm [last accessed
03 January 2003]. (Privately produced.)
Catlow, A., and Reeve, L. (1845). ‘The Conchologist’s Nomenclator;
A Catalogue of All the Recent Species of Shells, Included Under
the Subkingdom ‘Mollusca,’ with Their Authorities, Synonymes
[sic], and References to Works Where Figured or Described.’
(Reeve, Brothers: London, UK.)
Cernohorsky, W. O. (1972). ‘Marine shells of the Pacific,’ Volume II.
(Pacific Publications: Sydney, Australia.)
Chemnitz, J. H. (1784). ‘Neues Systematisches Conchylien-Cabinet.’
7, [i-xvi], 1–356. (Bauer und Raspe: Nürnberg.) [In ‘Index of
Rejected and Invalid Works in Zoological Nomenclature’; see
ICZN 1954].
Clayton, J. M. (1974). ‘All Color Book of Seashells.’ (Octopus Books:
London, UK.)
Coan, E. V., Valentich Scott, P., and Bernard, F. R. (2000). ‘Bivalve
Seashells of Western North America: Marine Bivalve Mollusks
from Arctic Alaska to Baja California.’ (Santa Barbara Museum of
Natural History: Santa Barbara, CA, USA.)
Cockerell, T. D. A. (1894). A list of the Brachiopoda, Pelecypoda,
Pteropoda, and Nudibranchiata of Jamaica, living and fossil. The
Nautilus 7(10), 113–118.
Cohen, S., and Cohen, R. (1991). ‘Florida Keys Diver’s Guide: The
Upper Keys.’ (Seapen Books: Key Largo, FL, USA.)
Coleman, N. (1981). ‘What Shell Is That?,’ 2nd ed. (Lansdowne Press:
Sydney, Australia.)
Cox, L. R., and Hertlein, L. G. (1969). Family Limidae Rafinesque,
1815. In ‘Part N [Bivalvia], Mollusca 6, vols 1 and 2’; in ‘Treatise
on Invertebrate Paleontology’. (Ed. R. C. Moore.) pp. N385–N393.
(Geological Society of America and University of Kansas: Law-
rence, KA, USA.)
Cuvier, G. (1797 “1798”). ‘Tableau Élémentaire de l’Histoire Natu-
relle des Animaux.’ (Baudouin: Paris, France.) [published before 24
December 1797, see Cox and Hertlein 1969: N285].
Dakin, W. J. (1928). The eyes of Pecten, Spondylus, Amussium and
allied lamellibranchs, with a short discussion on their evolution.
Proceedings of the Royal Society of London. Series B. Biological
Sciences 103, 355–365.
Dall, W. H. (1885). List of marine Mollusca comprising the Quaternary
fossils and Recent forms from American localities between Cape
Hatteras and Cape Roque including the Bermudas. United States
Geological Survey Bulletin 24, 1–336.
Dall, W. H. (1886). Reports on the results of dredging, under the
supervision of Alexander Agassiz, in the Gulf of Mexico (1877–78)
and in the Caribbean Sea (1879–80), by the U. S. Coast Survey
Steamer “Blake,” Lieut. -Commander C. D. Sigsbee, U. S. N., and
Commander J. R. Bartlett, U. S. N., commanding. XXIX. Report on
the Mollusca. Part I. Brachiopoda and Pelecypoda. Bulletin of the
Museum of Comparative Zoology, Harvard University 12,
171–318.
Dall, W. H. (1889). A preliminary catalogue of the shell-bearing
marine mollusks and brachiopods of the southeastern coast of the
United States, with illustrations of many of the species. Bulletin of
the United States National Museum 1889(37), 1–121.
Dall, W. H. (1896). The mollusks and brachiopods of the Bahama
Expedition of the State University of Iowa. Bulletin from the
Laboratories of Natural History of the State University of Iowa
4(1), 12–27.
Dall, W. H. (1898). Contributions to the Tertiary fauna of Florida, with
especial reference to the silex-beds of Tampa and the Pliocene beds
of the Caloosahatchie River, including in many cases a complete
revision of the generic groups treated of and their American
Tertiary species. Part. IV 1. Prionodesmacea: Nucula to Julia. 2.
Telodesmacea: Teredo to Ervilia. Transactions of the Wagner Free
Institute of Science, Philadelphia 3(4), 571–947.
Dall, W. H., and C. T. Simpson. (1901). The Mollusca of Porto Rico.
United States Fish Commission Bulletin for 1900 20(1), 351–524.
Dartevelle, E. (1934). Les perles fossils. Journal de Conchyliologie
78(3), 169–175.
Dance, S. P. (1974). ‘The Collector’s Encyclopedia of Shells.’
(McGraw-Hill: New York, USA.)
Dautzenberg, P. (1927). ‘Mollusques provenant des campagnes scienti-
fiques du Prince Albert 1er de Monaco dans l’Océan Atlantique et
dans le Golfe de Gascogne.’ Résultats des Campagnes Scientifiques
Accomplies sur son Yacht par Albert 1er Prince Souverain de
Monaco, Fascicule LXXII. (Imprimerie de Monaco.)
Dautzenberg, P., and H. Fischer. (1897). Campagnes scientifiques se
S. A. le Prince Albert Ier de Monaco. Dragages effectués par
l’Hirondelle et par la Princesse-Alice, 1888–1896. Mémoires de la
Société Zoologique France 10, 139–234.
Deshayes, G. P. (1830–1832). ‘Encyclopédie Méthodique. Histoire
Naturelle des Vers.’ Vol. 2, Part 1: i–viii, 1–256 (1830); Part 2:
1–144 (1830); 145–594 (1832); Vol. 3: 595–1152 (1832). (Agasse:
Paris, France.)
de Suduiraut, E. G. (2002 [ver. 04 May 2002]). ‘Eurasia Shells:
Iconographia of the Philippine Malacofauna.’ http://hal2001.
bizland.com/eurasiashells/fam_limidae.html [last accessed
02 January 2003]. (Privately produced: Cebu, Philippines.)
Diaz Merlano, J. M., and Puyana Hegedus, M. (1994). ‘Moluscos del
Caribe Colombiano: un Catálogo Ilustrado.’ (Colciencias y Funda-
ción Natura Colombia: Santafe de Bogota, Colombia.)
Dillwyn, L. W. (1817). ‘A Descriptive Catalogue of Recent Shells,
Arranged According to the Linnaean Method; with Particular
Attention to the Synonymy.’ Volume 1. (John and Arthur Arch:
London, UK.)
Dodge, H. (1952). A historical review of the mollusks of Linnaeus,
Part I. The classes Loricata and Pelecypoda. Bulletin of the
American Museum of Natural History 100(1), 1–263.
d’Orbigny, A. D. (1935–1846). ‘Voyage dans l’Amérique méridionale
(le Brésil, la république orientale de l’Uruguay, la république
Argentine, la Patagonie, la république du Chili, la république de
Bolivia, la république du Pérou), execute pendant les années 1826,
1827, 1828, 1829, 1830, 1831, 1832, et 1833. Tome Cinquième, 3.e
Partie: Mollusques.’ (Pitois-Levrault: Paris, France.) [Limidae:
pp. 651–654, 1846; for collation, see Coan et al. 2000: 613].

Western Atlantic Limidae Invertebrate Systematics 705
d’Orbigny, A. D. (1842–1853). ‘Histoire Physique, Politique et Natu-
relle de l’Ile de Cuba, par M. Ramon de la Sagra, [Tome 5],
Mollusques,’ Tome Second. (Arthus Bertrand: Paris, France.)
[Limidae: plate dated 1842, text dated 1853.]
d’Orbigny, A. D. (1845–1855). ‘Historia Fisica, Politica y Natural de la
Isla de Cuba por D. Ramon de la Sagra, Secunda Parte, Historia
Natural, Tomo 5, Moluscos.’ Libreria de Arthus Bertrand: Paris,
and Establegimiento Tiografico de Don Francisco de P. Mellado:
Madrid, Spain.) [Limidae: text dated 1846, plate probably dated
1855.]
Eisenberg, J. M. (1981). ‘A Collector’s Guide to Seashells of the
World.’ (McGraw-Hill: New York, USA.)
Emerson, W. K., and Jacobson, M. K. (1976). ‘The American Museum
of Natural History Guide to Shells; Land, Freshwater, and Marine,
from Nova Scotia to Florida.’ (Alfred A. Knopf: New York, USA.)
Espinosa, J., and Ortea, J. (2001). Moluscos del Mar Caribe de Costa
Rica: desde Cahuita hasta Gandoca. Avicennia (suppl. 4), 1–77.
Espinosa, J., Ortea, J., and Valdés, A. (1994). Catálogo de los moluscos
bivalvos recientes del Archipiélago cubano. Avicennia 2, 109–129.
Evenhuis, N. L., and Petit, R. E. (2003). Corrections and additions to
the dating of the “Histoire Naturelle des Vers” and the Tableau
Encyclopédie (Ve r s , coquilles, mollusques et polypiers) portions of
the Encyclopédie Méthodique. Zootaxa 207, 1–4.
Fenner, R. (2002 [ver. 04 April 2002]). ‘The Conscientious Marine
Aquarist: Bivalves, Clams, Class Bivalvia.’ http://www.
wetwebmedia.com/bivalvia.htm [last accessed 06 January 2003].
(WetWeb Media, Aquariums, Fish and Aquatic Information: San
Diego, CA, USA.)
Fischer, P. (1882). Diagnoses d’espèces nouvelles de mollusques
recueillis dans le cours des expeditions scientifiques de l’aviso le
Travailleur (1880 et 1881). Journal de Conchyliologie 30, 49–53.
Fondas, J. (2002). ‘Sailor’s Valentines.’ (Rizzoli International Publi-
cations: New York, USA.)
García, E. F., and Lee, H. G. (2002). Report on molluscan species
found in the offshore waters of Louisiana, including many exten-
sions of known range and un-named species. American Conch-
ologist 30(4), 10–13. [Also http://www.jaxshells.org/efg1030.htm,
last accessed 03 February 2003. ].
Gardner, J. (1926). The molluscan fauna of the Alum Bluff group of
Florida. Part I. Prionodesmacea and Anomalodesmacea. United
States Geological Survey Professional Papers 142-A, 1–79.
Gilmour, T. H. J. (1963a). A note on the tentacles of Lima hians
(Gmelin) (Bivalvia). Proceedings of the Malacological Society of
London 35(2–3), 81–85.
Gilmour, T. H. J. (1963b). ‘Studies on the Limidae.’ PhD Thesis.
(University of Glasgow: UK.)
Gilmour, T. H. J. (1967). The defensive adaptations of Lima hians
(Mollusca, Bivalvia). Journal of the Marine Biological Association
of the United Kingdom 47(1), 209–221.
Gilmour, T. H. J. (1974). The structure, ciliation, and function of the
lips of some bivalve molluscs. Canadian Journal of Zoology 52(3),
335–343.
Gilmour, T. H. J. (1990). The adaptive significance of foot reversal in
the Limoida. In ‘Proceedings of a Memorial Symposium in Honor
of Sir Charles Maurice Yonge (1899–1986), Edinburgh, 1986’.
(Ed. B. S. Morton.) pp. 249–263. (Hong Kong University Press:
Hong Kong.)
Giribet, G., and Wheeler, W. (2002). On bivalve phylogeny: a high-
level analysis of the Bivalvia (Mollusca) based on combined
morphology and DNA sequence data. Invertebrate Biology 121,
271–324.
Glémarec, M. (1978). Distribution bathymetrique and latitudinale des
bivalves du Golfe de Gascoigne. Haliotis 9(2), 23–32.
Gmelin, J. F. (1791). ‘Caroli a Linné … Systema Naturae per Regna
Tria Naturae, Secundum Classes, Ordines, Genera, Species, cum
Characteribus, Differentiis, Synonymis, Locis.’ Editio Decima
Tertia, Aucta, Reformata. 1(6), 3021–3909. (G. E. Beer: Leipzig,
Germany.)
Gómez, J. A, Liñero, I., and J. Fermín. (1995). Estudios ecologicos
sobre Lima scabra (Born, 1778) (Pelecypoda: Limidae) en el Golfo
de Cariaco, Venezuela. I. Censo y relaciones morfometricas.
Boletín del Instituto Oceanográfico de la Universidad de Oriente
34(1–2), 109–119.
Gordon, N. R. (1990). ‘Seashells: a Photographic Celebration.’
(Mallard Press: New York, USA.)
Goto, Y., and Poppe, G. T. (1996). ‘A Listing of Living Mollusca.’ Part
I (in 2 vols.), Part II (in 2 vols.). (L’Informatore Piceno: Ancona,
Italy.)
Gray, J. E. (1840). Mollusks. In ‘Synopsis of the Contents of the British
Museum,’ 42nd ed. pp. 86–89, 106–156. (G. Woodfall and Son:
London.) [Here citing the second issue of 4 November 1840; see
Kabat (1989).]
Gray, J. E. (1847). A list of the genera of Recent Mollusca, their
synonyma and types. Proceedings of the Zoological Society of
London 15, 129–219.
Great Barrier Reef Marine Park Authority (with assistance of
L. Cannon, L. Newman, and D. Hopley). (1995). ‘Barrier Reef; the
Multimedia Experience.’ CD-ROM. (Webster Publishing: Sydney,
Australia.)
Griffin, L. E. (1911). The structure of the pallial tentacles of Lima
species. Philippine Journal of Science 6(6), 327–328.
Hall, F. W. (1952). ‘Shells of the Florida Coasts: a Shell Pamphlet for
Amateurs.’ (Privately published: Jacksonville Beach, FL, USA.)
Hamann, B. (1987). Bivalve acrobatics. Busycon (Broward Shell Club,
Ft. Lauderdale, Florida) 22(1), 5.
Harry, H. (1982). Lima pellucida C. B. Adams, 1846 from Port Isabel,
Texas. Texas Conchologist 18(2), 43–45.
Haywood, M., and Wells, S. (1989). ‘The Manual of Marine Inverte-
brates.’ (Tetra Press, Salamander Books: Blacksburg, VA, USA.)
Heilprin, A. (1887). Explorations on the west coast of Florida and in
the Okeechobee wilderness. Transactions of the Wagner Free
Institute of Science 1, 365–506. [1972 reprint, Paleontological
Research Instution: Ithaca, NY, USA.]
Hemmen, J., and Hemmen, C. (1979). Beitrag zur Kenntnis der
Meeresmollusken-Fauna der Karibischen See. Grenada. Jahr-
bücher des Nassauischen Vereins für Naturkunde 104, 137–172.
Hertlein, L. G., and A. M. Strong. (1946). Eastern Pacific expeditions
of the New York Zoological Society. XXXIV. Mollusks from the
west coast of Mexico and Central America. Part III. New York
Zoological Society, Zoologica 31(2), 53–76.
Hesse, R. (1900). Untersuchungen über die Organe der Lichtempfind-
ung bei niederen Thieren. VI. Die Augen einiger Mollusken.
Zeitschrift fürWissenschaftliche Zoologie 68(3), 379–477.
Hesse, R. (ed.). (1928). ‘Nomenclator Animalium Generum et Sub-
generum.’ Zweiter Band C-E. Lieferung 8, 797–956. (Preußische
Akademie der Wissenschaften: Berlin, Germany.)
Hesse, R. (ed.). (1940). ‘Nomenclator Animalium Generum et Sub-
generum.’ Fünfter Band Q-Z. Lieferung 25, 2533–3692.
(Preußische Akademie der Wissenschaften: Berlin, Germany.)
Hickman, C. P., Jr., and Y. Finet. (1999). ‘A Field Guide to Marine
Molluscs of Galápagos; An Illustrated Guidebook to the Common
Intertidal and Shallow-Water Snails, Bivalves, and Chitons of the
Galápagos Islands.’ (Sugar Spring Press: Lexington, VA, USA.)
Hill, L., and Carmichael, P. (1995). ‘The World’s Most Beautiful
Seashells.’ (Carmichael Publications: Tampa, FL, USA.)
Hornsby, A. (2000). Jumpin’ jehoshaphat! Skin Diver 49(2), 26.

706 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
Houbrick, J. R. (1968). A survey of the littoral marine mollusks of the
Caribbean coast of Costa Rica. The Veliger 11(1), 4–23.
Humann, P. (1992). ‘Reef Creature Identification; Florida, Caribbean,
Bahamas.’ (New World Publications: Jacksonville, FL, USA.)
Humann, P., and DeLoach, N. (2002). ‘Reef Creature Identification;
Florida, Caribbean, Bahamas.’ (New World Publications: Jackson-
ville, FL, USA.)
Humfrey, M. (1975). ‘Sea Shells of the West Indies; A Guide to the
Marine Molluscs of the Caribbean.’ (Taplinger: New York, USA.)
Humphrey, G. (1797). “Museum Calonnianum. Specification of the
Various Articles which Compose the. Museum of Natural History,
Collected by M. de Calonne in France.’ Part 1. (London.) [Not
seen; on ‘Index of Rejected and Invalid Works in Zoological
Nomenclature’; see ICZN 1956b.]
Hutsell, K. C., Hutsell, L. L., and Pisor, D. L. (1997). ‘Hutsell and
Pisor’s Registry of World Record Size Shells.’ (Snail’s Pace Pro-
ductions: San Diego, CA, USA.)
INBiol [Instituto Nacional de Biodiversidad]. (2001). ‘Biodiversity of
Costa Rica.’ http://www.inbio.eas.ualberta.ca/attaing/index.htm
[Last accessed 02 January 2003.] (Instituto Nacional de Biodiver-
sidad: Santo Domingo de Heredia, Costa Rica.)
International Commission on Zoological Nomenclature (ICZN)
(1912). Opinion 51. Shall the Names of Museum Calonnianum,
1797, be accepted? Opinions rendered by the International Com-
mission on Zoological Nomenclature, Opinions 38 to 51. Smith-
sonian Publications 2060, 89–117.
International Commission on Zoological Nomenclature (ICZN)
(1954). Direction 1: Addition to the Official Lists and Official
Indexes of certain scientific names and of the titles of certain books
dealt with in Opinions 182 to 194. Opinions and Declarations.
International Commission on Zoological Nomenclature 3(30),
401–416 [re Chemnitz 1784].
International Commission on Zoological Nomenclature (ICZN)
(1956a). Opinion 417. Rejection for nomenclatorial purposes of
volume 3 (Zoologie) of the work by Lorenz Oken entitled Okens
Lehrbuch der Naturgeschichte published in 1815–1816. Opinions
and Declarations. International Commission on Zoological
Nomenclature 14(1), 1–42.
International Commission on Zoological Nomenclature (ICZN).
(1956b). Direction 32. Opinions and Declarations, International
Commission on Zoological Nomenclature 1C(C. 21), 307–328 [see
p. 319, re Humphrey 1797].
International Commission on Zoological Nomenclature (ICZN)
(1956c). Opinion 427. Rejection for nomenclatorial purposes of the
work by Renier (S. A.) known as Tavole per servire alle classifica-
zione e connescenza degli animali and commonly attributed to the
year 1807…. Opinions and Declarations. International Commis-
sion on Zoological Nomenclature 14(11), 281–310.
International Commission on Zoological Nomenclature (ICZN)
(1999). ‘International Code of Zoological Nomenclature,’ 4th ed.
(International Trust for Zoological Nomenclature: London, UK.)
Iredale, T. (1929). Mollusca from the continental shelf of eastern
Australia. No. 2. Records of the Australian Museum 17(4),
157–189.
ITIS [Integrated Taxonomic Information System]. (2002a [ver. 19
June]). ‘ITIS report: Lima floridana Olsson and Harbison, 1953.’
(United States Department of Agriculture: Washington, DC, USA.
http://www.itis.usda.gov/servlet/SingleRpt/SingleRpt?search_topic
=TSN&search_value=79823 [last accessed 19 June 2003].)
ITIS [Integrated Taxonomic Information System]. (2002b [ver.
19 June]). ‘ITIS report: Lima tenera Sowerby, 1843.’ (United States
Department of Agriculture: Washington, DC, USA. http://www.
itis.usda.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&
search_value=79821 [last accessed 19 June 2003].)
Jackson, J. W. (1909). On some fossil pearl growths. Proceedings of the
Malacological Society of London 8, 318–320.
Jacobson, M. K., and L. Hernandez. (1973). An unusual habitat for the
rough file shell, Lima scabra (Born, 1780). The Veliger 16(1),
85–86.
Jaume, M. L. (1946). Moluscos marinos litorales del Cabo Catoche,
Yucatán, México. Revista de la Sociedad Malacólogica “Carlos de
la Torre” 4(3), 95–110.
Jaume, M. L., and I. Pérez Farfante. (1942). Moluscos Pleistocenicos
de la zona franca de Matanzas. Memorias de la Sociedad Cubana
de Historia Natural “Felipe Poey” 16(1), 37–44.
Jensen, R. H., and Harasewych, M. G. (1986). Class Bivalvia. In
‘Marine Fauna and Flora of Bermuda; a Systematic Guide to the
Identification of Marine Organisms’. (Ed. W. Sterrer.) pp. 460–491.
(John Wiley and Sons: New York, USA.)
Johnson, C. W. (1934). List of marine Mollusca of the Atlantic coast
from Labrador to Texas. Proceedings of the Boston Society of
Natural History 40(1), 1–204.
Johnson, S. (1982). ‘Living Seashells.’ (Oriental: Honolulu.)
Kabat, A. R. (1989). The “Gray Catalogues” [Mollusca] of the British
Museum. The Nautilus 103(3), 113–115.
Kaplan, E. H. (1982). ‘A Field Guide to Coral Reefs of the Caribbean
and Florida; a Guide to the Common Invertebrates and Fishes of
Bermuda, the Bahamas, Southern Florida, the West Indies, and the
Caribbean Coast of Central and South America.’ Peterson Field
Guide no. 27. (Houghton Mifflin: Boston, MA, USA.)
Kaplan, E. H. (1988). ‘A Field Guide to Southeastern and Caribbean
Seashores; Cape Hatteras to the Gulf Coast, Florida, and the
Caribbean.’ Peterson Field Guide no. 36. (Houghton Mifflin:
Boston, MA, USA.)
Kay, E. A., and Schoenberg-Dole, O. (1991). ‘Shells of Hawai’i.’
(University of Hawaii Press: Honolulu.)
Kennedy, M. (1969). Anchors aweigh! Seafari 11(4), 6–7.
Kilburn, R. N. (1998). The Limidae of South Africa and Mozambique
(Mollusca: Bivalvia): genera Limaria, Limatula, Divarilima,
Ctenoides and Fukama. Annals of the Natal Museum 39, 203–247.
Klein, J. T. (1753). ‘Tentamen Methodi Ostracologicae Sive Dispositio
Naturalis Cochlidium et Concharum in Suas Classes, Genera et
Species.’ (G. J. Wishoff: Lugduni Batavorum [Leiden, The Nether-
lands].)
Knorr, G. W. (1772). ‘Vergnügen der Augen und des Gemüths, in
Vorstellung einer allgemeinen Sammlung von Schnecken und
Muscheln, welche im Meer gefunden werden.’ Sechster Theil.
(G. W. Knorr Erben: Nuremberg, Germany.)
Kraeuter, J., Adamkewicz, L., Castagna, M., Wall, R., and Karney, R.
(1984). Rib number and shell color in hybridized subspecies of the
Atlantic bay scallop, Argopecten irradians. The Nautilus 98(1),
17–20.
Lacaze-Duthiers, H. (1854). Recherches sur les organs génitaux des
acéphales lamellibranches. Annales des Sciences Naturelles, 4th
ser., Zoologie 2, 155–248.
Lamarck, J. B. (1807 [January?] “1806”). Suite des Mémoires sur les
fossils des environs de Paris. Annales du Museum d’Histore
Naturelle 8, 461–469.
Lamarck, J. B. (1819). ‘Histoire Naturelle des Animaux sans Vertebres,
Présentant les Caractères Généraux et Particuliers de ces Animaux,
leur Distribution, leurs Classes, leurs Familles, leurs Genres, et la
Citation des Principales Espèces qui s’y Rapportent.’ Volume 6.
(Lamarck: Paris, France.)
Lamy, E. (1930–1931). Révision des Limidae vivants du Muséum
national d’Histoire naturelle de Paris. Journal de Conchyliologie
74[(4)28](2), 89–114 [1930]; (3), 169–198 [1930]; (4), 245–269
[1931].
Lawson, B. (1993). ‘Shelling San Sal.’ (Bahamian Field Station: San
Salvador, Bahamas.)

Western Atlantic Limidae Invertebrate Systematics 707
Lee, H. G. (2002) [ver. 22 September 2002]). ‘Marine Shells from
Northeast Florida.’ http://www.jaxshells.org/marine.htm [Last
accessed 03 Februray 2003.] (Jacksonville Shell Club: Jackson-
ville, FL, USA.)
Lindner, G. (1977). ‘Field Guide to Seashells of the World,’ English ed.
(Van Nostrand Reinhold: New York, USA.)
Lin, A. R., and L. A. Pompa. (1977). Carotenoids of the red clam Lima
scabra. Boletín del Instituto Oceanográfico de Venezuela, Universi-
dad de Oriente 16(1–2), 83–86.
Link, H. F. (1807 [17 May]). ‘Beschreibung der Naturalien-Sammlung
der Universität zu Rostock.’ Dritte Abtheilung. (Adler’s Erben:
Rostock, Germany.)
Linné, C. (1758). ‘Systema Natura per Regna Tria Naturae, Secundum
Classes, Ordines, Genera, Species cum Characteribus, Differentiis,
Synonymis, Locis.’ Tomus I, 10th ed. (L. Salvii: Stockholm,
Sweden.)
Lipe, R. E., and Abbott, R. T. (1991). ‘Living Shells of the Caribbean
and Florida Keys.’ (American Malacologists: Melbourne, FL,
USA.)
Lipka, D. A. (1974). Mollusks. In ‘Biota of the West Flower Garden
Bank’. (Eds T. J. Bright and L. H. Pequegnat.) pp. 141–196. (Gulf
Publishing Company: Houston, TX, USA.)
Lister, M. (1685–1692). ‘Historiae Conchyliorum.’ (M. Lister, Lon-
don.) [for full collation, see Wilkins 1957].
LiveAquaria com. (2003). LiveAquaria. com: quality aquatic life direct
to your door. http://www.liveaquaria.com/default.cfm?siteid=20
[last accessed 24 February 2003]. (Privately produced: Rhine-
lander, Wisconsin.)
Locard, A. (1898). ‘Expéditions Scientifiques du Travailleur et du
Talisman Pendant les Années 1880, 1881, 1882, 1883.’ Mollusques
testacés, 2, 1–515. (Masson et Cie: Paris, France.)
Lodeiros, C. J., and Himmelman, J. H. (1999). Reproductive cycle of
the bivalve Lima scabra (Pterioidea: Limidae) and its association
with environmental conditions. Revista de Biologia Tropical 47(3),
411–418.
Lozet, J. B., and Pétron, C. (1977). ‘Shells of the Caribbean,’ (English
edition; Eds W. and S. Reed.) (Les Éditions du Pacifique: Tahiti.)
Lutz, P. E. (1986). ‘Invertebrate Zoology.’ (Benjamin/Cummings:
Menlo Park, CA, USA.)
Lyman, F. (1944). Treasure hunting. Shell Notes 1(10), 75–77, 80–82.
Lyons, B. (1992). Collecting marine mollusks in Florida: rules of the
game. AMU [American Malacological Union] News 23(1), 13–14.
[Reprinted in Texas Conchologist 29(1), 19–20.]
Lyons, W. G., and Quinn, J. F., Jr (1995). Appendix J. Marine and
terrestrial species and algae: Phylum Mollusca. In ‘Florida Keys
National Marine Sanctuary Draft Management Plan/Environmental
Impact Statement. Volume III. Appendices’. (Eds B. Causey and
E. Lindelof.) pp. J10–J26. (National Oceanographic and Atmos-
pheric Administration: Silver Spring, MD, USA.)
Magnotte, G. (1970–1979). ‘Shelling and Beachcombing in Southern
and Caribbean Waters.’ (International Graphics: Hollywood, FL,
USA.)
Manning, R. B., and Kumpf, H. E. (1959). Preliminary investigation of
the fecal pellets of certain invertebrates of the South Florida area.
Bulletin of Marine Science of the Gulf and Caribbean 9(3),
291–309.
Marelli, D. C., Krause, M. K., Arnold, W. S., and Lyons, W. G. (1997).
Systematic relationships among Florida populations of Argopecten
irradians (Lamarck, 1819) (Bivalvia: Pectinidae). The Nautilus
110(2), 31–41.
Martínez, E., Rodríguez, G., and Rodríguez, M. J. (1993). Moluscos
testáceos recolectados durante la campaña oceanográfica CAP–89
en aguas profundas de Asturias (N de España). Iberus 11(2), 67–73.
Martynov, A. V. (2002). The shell collection of J. H. Chemnitz in the
Zoological Institute, St. -Petersburg. Ruthenica 12(1), 1–18.
Maury, C. J. (1920). Recent molluscs of the Gulf of Mexico and
Pleistocene and Pliocene species from the Gulf states. Part 1.
Pelecypoda. Bulletins of American Paleontology 8(34), 35–147.
McLean, R. A. (1951). The Pelecypoda or bivalve mollusks of Porto
Rico and the Virgin Islands. New York Academy of Sciences,
Scientific Survey of Puerto Rico and the Virgin Islands 17(1),
1–183.
Melvin, A. G., and L. S. Melvin. (1980). ‘1,000 World Sea Shells; Rare
to Common, with Values.’ (Charles E. Tuttle: Rutland, Germany.)
Merrill, A. S., and Petit, R. E. (1969). Mollusks new to South Carolina:
II. The Nautilus 82(4), 117–122.
Merrill, A. S., and Turner, R. D. (1963). Nest building in the bivalve
genera Musculus and Lima. The Veliger 6(2), 55–59.
Mikkelsen, P. M., and Bieler, R. (1998). File clams and flame scallops
in the western Atlantic (Bivalvia: Limidae). In ‘Abstracts, World
Congress of Malacology, Washington, DC’. (Eds R. Bieler and
P. M. Mikkelsen.) p. 223. (Unitas Malacologica: Chicago, IL,
USA.) [Also published in Western Society of Malacologists Annual
Report (for 1997/1998) 31, 15–16.]
Mikkelsen, P. M., and Bieler, R. (2000). Marine bivalves of the Florida
Keys: discovered biodiversity. In ‘The Evolutionary Biology of the
Bivalvia’. (Eds E. M. Harper, J. D. Taylor and J. A. Crame.)
pp. 367–387. (Geological Society Special Publication 177:
London, UK.)
Mikkelsen, P. M., and Bieler, R. (2001). Varicorbula (Bivalvia: Corbul-
idae) of the western Atlantic: taxonomy, anatomy, life habits, and
distribution. The Veliger 44(3), 271–293.
Mörch, O. A. L. (1853). ‘Catalogus Conchyliorum Quae Reliquit D.
Alphonso d’Aguirra and Gadea Comes de Yoldi, Regis Daniae
Cubiculariorum Princeps, Ordinis Dannebrogici in Prima Classe
and Ordinis Caroli Tertii Eques. Fasciculus Secundus. Acephala.
Annulata Cirripedia. Echinodermata.’ (L. Klein: Hafniae [Copen-
hagen, Denmark].)
Morris, P. A. (1973). ‘A Field Guide to Shells of the Atlantic and Gulf
Coasts and the West Indies,’ 3rd ed. Peterson Field Guide no. 3.
(Houghton Mifflin: Boston, MA, USA.)
Morton, B. S. (1979). A comparison of lip structure and function
correlated with other aspects of the functional morphology of Lima
lima, Limaria (Platilimaria) fragilis, and Limaria (Platilimaria)
hongkongensis sp. nov. (Bivalvia: Limacea). Canadian Journal of
Zoology 57(4), 728–742.
Morton, B. S. (2000). The pallial eyes of Ctenoides floridanus
(Bivalvia: Limoidea). The Journal of Molluscan Studies 66(4),
449–455.
Mpitsos, G. J. (1973). Physiology of vision in the mollusk Lima
scabra. Journal of Neurophysiology 36(2), 371–383.
Nordsieck, F. (1969). ‘Die europäischen Meeresmuscheln (Bivalvia)
vom Eismeer bis Kapverden, Mittelmeer und Schwarzes Meer.’
(Gustav Fischer Verlag: Stuttgart, Germany.)
Nowell-Usticke, G. W. (1959). ‘A Check List of the Marine Shells of
St. Croix, U. S. Virgin Islands, with Random Notations.’ (Lane
Press: Burlington, VT, USA.)
Odé, H. (1979). Distribution and records of the marine Mollusca in the
northwest Gulf of Mexico (a continuing monograph). Texas Conch-
ologist 16(1), 14–32.
Odé, H. (1988). Observations on a naughty beach. Texas Conchologist
25(1), 10–25.
Odé, H., and Speers, B. (1965). Notes concerning Texas beach shells.
Texas Conchologist 2(1), 2–3.
Oken, L. (1815). ‘Okens Lehrbuch der Naturgeschichte.’ Dritter Theil:
Zoologie. Erste Abtheilung: Fleischlose Thiere. (A. Schmid and
Company: Jena.) [In ‘Index of Rejected and Invalid Works in
Zoological Nomenclature’; see ICZN 1956a.]

708 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
Okubo, S., Kurokawa, T., Suzuki, T., Funakoshi, S., and Tsujii, T.
(1997). On the mechanism of streak-like flash on the mantle of
Ctenoides ales (Bivalvia: Limidae). Venus (Fukuyama-Shi, Japan)
56(3), 259–269.
Okutani, T. (1994). A new discovery of streak-like flashing lumines-
cence in Ctenoides ales (Finlay, 1927) (Bivalvia: Limidae). Venus
(Fukuyama-Shi, Japan) 53(1), 57–59.
Oliver, P. G. (1987). ‘The Melvill-Tomlin Collection. Part 47.
Limacea.’ Handlists of the Molluscan Collections in the Depart-
ment of Zoology. (National Museum of Wales: Cardiff, Wales.)
Oliver, P. G. (1992). ‘Bivalved Seashells of the Red Sea.’ (Verlag
Christa Hemmen: Wiesbaden, and National Museum of Wales:
Cardiff, Wales.)
Olsson, A. A., and A. Harbison. (1953). Pliocene Mollusca of southern
Florida with special reference to those from North Saint Peters-
burg. Monographs of the Academy of Natural Sciences of Phila-
delphia 8, 457 pp. [1979 Reprint]
Oyama, K. (1943). Familia Limidae. Conchologica Asiatica 1(1),
1–74.
Palmer, K. V. W. (1947). Manuscript notes by P. P. Carpenter on
d’Orbigny’s series of Cuban shells in the British Museum. Memo-
rias de la Sociedad Cubana de Historia Natural 19(1), 89–104.
Parker, R. H. (1960). Ecology and distributional patterns of marine
macro-invertebrates, northern Gulf of Mexico. In ‘Recent Sedi-
ments, Northwest Gulf of Mexico, 1951–1958’. (Eds F. P. Shepard,
F. B. Phleger and T. H. van Andel.) pp. 302–337. (American
Association of Petroleum Geologists: Tulsa, OK, USA.)
Parodiz, J. J. (c. 1976). ‘Marine Mollusca collected in Yucatan.’
(Privately distributed, Philadelphia). [Copy deposited in the mollus-
can libraries at AMNH and FMNH.]
Peeters, I., and Exbrayat, A. (1990). ‘Coquillages, Shells’. (Editions
Exbrayat: Fort-de-France, Martinique.)
Peile, A. J. (1926). The Mollusca of Bermuda. Proceedings of the
Malacological Society 17(2–3), 71–98.
Pelseneer, P. (1906). Un genre de lamellibranches à bouches multiples.
Comptes Rendus Hebdomadaires des Séances l’Académie des
Sciences. Paris 142, 722–723.
Pelseneer, P. (1907). La concentration du système nerveux chez les
lamellibranches. Académie Royale de Belgique, Bulletin de la
Classe des Sciences 1907(2), 874–878.
Pelseneer, P. (1911). ‘Les Lamellibranches de l’Expedition du Siboga.
Partie Anatomique.’ Siboga-Expeditie, 53a. (E. J. Brill: Leiden, The
Netherlands.)
Pelseneer, P. (1931). Quelques particularités d’organisation chez des
Pectinacea. Annales de la Societe Royale Zoologique de Belgique
61, 12–17.
Petit, R. E., and Harasewych, M. G. (1990). Catalogue of the super-
family Cancellarioidea Forbes and Hanley, 1851 (Gastropoda:
Prosobranchia). The Nautilus 103(suppl. 1), 1–69.
Petit de la Saussaye, S. (1853). Supplément au catalogue des coquilles
trouvées à l’ile de la Guadeloupe, par M. Beau. Journal de
Conchyliologie 4, 413–419.
Plockelman, C. (1970a). Spondylus: home, nursery, trash can. Seafari
12(11), 1–5.
Plockelman, C. H. (1970b). April in Bear Cut. Seafari 12(5), 12.
Pointier, J.-P., and Lamy, D. (1998). ‘Guide des Coquillages des
Antilles.’ (PLB Editions: Guadeloupe.)
Poppe, G. T., and Goto, Y. (1993). ‘European Seashells.’ Volume II.
(Verlag Christa Hemmen: Wiesbaden, Germany.)
Porter, H. J. (1971). Record sizes of North Carolina mollusks. List no.
2. North Carolina Shell Club Bulletin (6), 29–34.
Porter, H. J., and Houser, L. (1998). ‘Seashells of North Carolina.’
(North Carolina Sea Grant College Program: Raleigh, NC, USA.)
Pulley, T. E. (1952). ‘A Zoogeographic Study Based on the Bivalves of
the Gulf of Mexico.’ PhD Thesis. (Harvard University, Cambridge,
MA, USA.)
Purchon, R. D. (1957). The stomach in the Filibranchia and Pseudo-
lamellibranchia. Proceedings of the Zoological Society of London
129, 27–60.
Purchon, R. D. (1987). The stomach in the Bivalvia. Philosophical
Transactions of the Royal Society of London B 316, 183–276.
Rafinesque, C. S. (1815). ‘Analyse de la Nature, ou Tableau de
l’Univers et des Corps Organisés.’ (Palermo, Italy.)
Raines, B. K. (2002). Contributions to the knowledge of Easter Island
Mollusca. La Conchiglia 34(304), 11–40.
Read, K. R. H. (1967). Thermal tolerance of the bivalve mollusc Lima
scabra Born, in relation to environmental temperature. Proceedings
of the Malacological Society of London 37(4), 233–241.
Redfern, C. (2001). ‘Bahamian Seashells: a Thousand Species from
Abaco, Bahamas.’ (Bahamianseashells. com: Boca Raton, FL,
USA.)
Reef Topia (2002). ‘WWW. REEFTOPIA. COM: buy directly from the
diver and save!’ http://www.reeftopia.com/index.htm [last accessed
24 February 2003]. (Privately produced: Florida Keys, USA.)
Rehder, H. A. (1981). ‘The Audubon Society Field Guide to North
American Seashells.’ (Alfred A. Knopf: New York, USA.)
Renier, S. A. (1807). ‘Tavole per Servire alle Classificazione e
Connescenza degli Animali.’ (Padua.) [In ‘Index of Rejected and
Invalid Works in Zoological Nomenclature’; see ICZN 1956c.]
Rice, W. H., and L. S. Kornicker. (1962). Mollusks of Alacran Reef,
Campeche Bank, Mexico. Publications of the Institute of Marine
Science, University of Texas 8, 366–403.
Ridewood, W. G. (1903). On the structure of the gills of the Lamelli-
branchia. Philosophical Transactions of the Royal Society of
London B 195(5), 147–284.
Ring, F. McC. (1980). Of coral reefs, intertidal shores and sand flats in
the Florida Keys. Of Sea and Shore 11(2), 129–135.
Rios, E. de C. (1970). ‘Coastal Brazilian Seashells.’ (Museu Oceano-
grafico: Rio Grande, Brazil.)
Rios, E. de C. (1975). ‘Brazilian Marine Mollusks Iconography.’
(Fundação Universidade do Rio Grande, Centro de Ciencias do
Mar, Museu Oceanográfico: Rio Grande, Brazil.)
Rios, E. de C. (1994). ‘Seashells of Brazil,’ 2nd ed. (Fundação Cidade
do Rio Grande, Museu Oceanográfico “Prof. Eliézer de Carvalho
Rios”: Rio Grande, Brazil.)
Ripple, J. (1995). ‘The Florida Keys; the Natural Wonders of an Island
Paradise.’ (Voyageur Press: Stillwater, Minnesota, USA.)
Röding, P. F. (1798). ‘Museum Boltenianum sive Catalogus Cimelio-
rum e Tribus Regnis Naturae… Pars Secunda Continens Conchylia
sive Testacea Univalvia, Bivalvia and Multivalvia.’ (J. C. Trapp:
Hamburg, Germany.)
Rogers, J. E. (1951). ‘The Shell Book, a Popular Guide to a Knowledge
of the Families of Living Mollusks, and an Aid to the Identification
of Shells Native and Foreign,’ rev. ed. [With updated taxonomic
index by H. A. Rehder.] (Doubleday, Page: New York, USA.)
Rolán, E. M., Otero, J. S., and Rolán, E. A. (1989). ‘Moluscos de la Ria
de Vigo II. Revista de Ciencias del Mar Thalassas.’ (Universidade
de Santiago de Compostela: Santiago de Compostela, Spain.)
Rosenberg, G. (1992). ‘The Encyclopedia of Seashells.’ (Dorset Press:
New York, USA.)
Rovereto, G. (1898). Note preventive sui pelecipodi del tongriano
ligure. II. Atti della Società Ligustica 9, 153–187.
Salvini-Plawen, L. von, and R. T. Abbott. (1984). Bivalves. In
‘Grzimek’s Animal Life Encyclopedia, Volume 3, Molluscs and
Echinoderms’. English ed. (Eds B. Grzimek, O. Kraus, R. Reidl
and E. Thenius.) pp. 143–189. (Van Nostrand Reinhold: New York,
USA.)

Western Atlantic Limidae Invertebrate Systematics 709
Sander, F., and C. M. Lalli. (1982). A comparative study of mollusk
communities on the shelf-slope margin of Barbados, West Indies.
The Veliger 24(4), 309–318.
Schramm, A. (1869). ‘Catalogues des Coquilles et des Crustacés de la
Guadeloupe envoyés a l’Exposition Universelle de 1867 par
l’Administration de la Colonie. Collections Caillet et I. Desbonne.
Déterminations et Classements. Deuxième Édition.’ (Basse-Terre:
The Netherlands.)
Schreiner, K. E. (1897). Die Augen bei Pecten und Lima. Bergens
Museums Aarbog 1896, 1–51.
Scudder, S. H. (1882). Nomenclator Zoologicus. An alphabetical list of
all generic names that have been employed by naturalists for Recent
and fossil animals from the earliest times to the close of the yeart
1879. In two parts: I. Supplemental List. II. Universal Index.
Bulletin of the United States National Museum 1882(19), i–xxii,
1–340.
Seydel, E. (1909). Untersuchungen über den Byssusapparat der Lamel-
libranchiaten. Zoologische Jahrbücher, Abteilung für Anatomie und
Ontogenie der Tiere 27(3), 465–582.
Sharabati, D. (1981). ‘Saudi Arabian Seashells; Selected Red Sea and
Arabian Gulf Molluscs.’ (VNU Books International.) [Place of
publication not indicated.]
Shelton, D. N. (1997). ‘A Systematic List of Mollusks in the Northern
Gulf of Mexico off the Coast of Alabama.’ (Alabama Malacologi-
cal Research Center: Mobile, AL, USA.) [Copy deposited in
molluscan library at AMNH.]
Simpson, C. T. (1887–1889). Contributions to the Mollusca of Florida.
Proceedings of the Davenport Academy of Natural Sciences 5,
45–72.
Smith, E. A. (1885). Report on the Lamellibranchiata collected by
H. M. S. Challenger, during the years 1873–1876. In ‘Report on the
Scientific Results of the Voyage of H. M. S. Challenger, Zoology,
13’. (Eds C. W. Thomson and J. Murray.) pp. 1–341. (British
Government: London, UK.)
Smith, M. (1937). ‘East Coast Marine Shells; Descriptions of Shore
Mollusks Together with Many Living Below Tide Mark, from
Maine to Texas Inclusive, Especially Florida’. (Edwards Brothers:
Ann Arbor, MI, USA.)
Smith, M. (1940). ‘World-Wide Sea Shells; Illustrations, Geographical
Range and Other Data Covering More than Sixteen Hundred
Species and Sub-species of Molluscs.’ (Tropical Photographic
Laboratory: Lantana, FL, USA.)
Smith, M. (1945). ‘East Coast Marine Shells; Descriptions of Shore
Mollusks Together with Many Living Below Tide Mark, from
Maine to Texas Inclusive, Especially Florida,’ 3rd ed. (Edwards
Brothers: Ann Arbor, MI, USA.)
Snyderman, M., and Wiseman, C. (1996). ‘Guide to Marine Life;
Caribbean, Bahamas, Florida.’ (Aqua Quest: New York, USA.)
Sokal, R. R., and Rohlf, F. J. (1981). ‘Biometry; the Principles and
Practice of Statistics in Biological Research,’ 2nd ed. (W. H. Freeman
and Company: New York, USA.)
Sowerby, G. B. (1825). ‘Genera of Recent and Fossil shells, for the Use
of Students in Conchology and Geology; Plates of Genera; also
Corresponding Letter-Press, Descriptive of the Characters by
which each Genus is Distinguished. Particularly the Land, Fresh
Water and Marine Nature of Each Genus, as well as the Strata in
which the Fossil Species Occur.’ Part 17, Lima. (G. B. Sowerby:
London, UK.)
Sowerby, G. B., II. (1843). Monograph of the genus Lima. In
‘Thesaurus Conchyliorum; or, Monographs of Genera of Shells’.
(Ed. G. B. Sowerby II.) 1(3), 83–88. (Sowerby: London, UK.)
Sowerby, G. B., II. (1854). ‘Popular British Conchology. A Familiar
History of the Molluscs Inhabiting the British Isles.’ (Lovell Reeve:
London, UK.)
Sowerby, G. B., II. (1872). Monograph of the genus Lima. In ‘Conch-
ologia Iconica; or, Illustrations of the Shells of Molluscous
Animals’. (Ed. L. A. Reeve, continued by G. B. Sowerby.) 18.
(L. Reeve and Company: London, UK.)
Stanley, S. M. (1970). Relation of shell form to life habits of the
Bivalvia (Mollusca). Geological Society of America, Memoirs 125,
i–xiii, 1–296.
Steiner, G., and Hammer, S. (2000). Molecular phylogeny of the
Bivalvia inferred from 18S rDNA sequences with particular refer-
ence to the Pteriomorpha. In ‘The Evolutionary Biology of the
Bivalvia’. (Eds E. M. Harper, J. D. Taylor and J. A. Crame.)
pp. 11–29. (Geological Society Special Publication 177: London,
UK.)
Stoliczka, F. (1870–1871). Cretaceous fauna of southern India, Vol. III:
The Pelecypoda, with a review of all known genera of this class,
fossil and Recent. Memoires of the Geological Survey of India,
Palaeontologica Indica, pp. i–xxii, 1–538. (1–222, 1 Sept. 1870;
223–408, 1 March 1871; xxii + 409–538, 1 Aug. 1871.)
Stuardo, J. (1982). A new species of Ctenoides from the central
Atlantic (Bivalvia: Limidae). Boletín de la Sociedad de Biología de
Concepción. Chile 53, 145–149.
Stuardo, J. R. (1968). ‘On the Phylogeny, Taxonomy and Distribution
of the Limidae (Mollusca: Bivalvia).’ PhD Thesis. (Harvard Uni-
versity: Cambridge, MA, USA.)
Sutty, L. (1990). ‘Seashells of the Caribbean.’ (MacMillan Press:
London, UK.)
Thiele, J. (1918–1920). Familia Limidae. Systematisches Conchylien-
Cabinet von Martini und Chemnitz 7(2a), 1–66, [1918: 1–24; 1920:
25–66].
Thiele, J. (1934). ‘Handbuch der systematischen Weichtierkunde.’
Zweiter Band, Dritter Teil: Scaphopoda. / Bivalvia. / Cephalopoda.
(Gustav Fischer Verlag: Jena, Germany.)
Tornaritis, G. (1987). ‘Mediterranean Sea Shells: Cyprus.’ (G. Torna-
ritis: Nicosia, Cyprus.)
Tryon, G. W. (1873–1874). ‘American Marine Conchology; or,
Descriptions of the Shells of the Atlantic Coast of the United States
from Maine to Florida.’ (Privately published: Philadelphia, PA,
USA.)
Turgeon, D. D., Quinn, J. F., Jr, Bogan, A. E., Coan, E. V.,
Hochberg, F. G., et al. (1998). ‘Common and Scientific Names of
Aquatic Invertebrates from the United States and Canada:
Mollusks,’ 2nd ed. American Fisheries Society Special Publication
26. (American Fisheries Society: Bethesda, MD, USA.)
Turton, W. (1825). Description of some new British shells; accompa-
nied by figures from the original specimens. The Zoological
Journal 2, 361–367.
Vilas, C. N., and Vilas, N. R. (1945). ‘Florida Marine Shells; a Guide
to [sic] Amateur Collectors of Florida Marine Shells which is
Completely Illustrated with Colored Photo-Engravings.’ (Aberdeen
Press: Chicago, IL, USA.)
Vokes, H. E. (1973). Notes on the fauna of the Chipola formation –
XIII: the family Limidae (Mollusca: Bivalvia). Tulane Studies in
Geology and Paleontology 10(2), 87–96.
Vokes, H. E., and E. H. Vokes. (1984 “1983”). Distribution of shallow-
water marine Mollusca, Yucatan Peninsula, Mexico. Mesoamerican
Ecology Institute, Monograph 1. Middle American Research Insti-
tute, Publication 54, 1–183.
von Studnitz, G. (1931). Die Morphologie und Anatomie von Lima
inflata, der Feilenmuschel, nebst biologischen Untersuchungen an
Lima hians Gmel. Zoologische Jahrbücher 53(2), 199–316.
Voss, G. L. (1976). ‘Seashore Life of Florida and the Caribbean.’
(E. A. Seemann: Miami, FL, USA.)

710 Invertebrate Systematics P. M. Mikkelsen and R. Bieler
http://www.publish.csiro.au/journals/is
Voss, G. L. (1980). ‘Seashore Life of Florida and the Caribbean; a
Guide to the Common Marine Invertebrates and Plants of the
Atlantic from Bermuda and the Bahamas to the West Indies and the
Gulf of Mexico,’ rev., and enlarged ed. (Banyan Books: Miami, FL,
USA.)
Waller, T. R. (1973). The habits and habitats of some Bermudian
marine mollusks. The Nautilus 87(2), 31–52.
Waller, T. R. (1976). The behavior and tentacle morphology of
pteriomorphian bivalves: a motion-picture study. Bulletin of the
American Malacological Union 1975, 7–13.
Waller, T. R. (1978). Morphology, morphoclines and a new classifi-
cation of the Pteriomorphia (Mollusca: Bivalvia). Philosophical
Transactions of the Royal Society of London B 284, 345–365.
Waller, T. R. (1998). Origin of the molluscan class Bivalvia and a
phylogenyof major groups. In ‘Bivalves: an Eon of Evolution;
Paleobiological Studies Honoring Norman D. Newell’.
(Eds P. A. Johnston and J. W. Haggart.) pp. 1–45. (University of
Calgary Press: Calgary, Canada.)
Warmke, G. L., and Abbott, R. T. (1961). ‘Caribbean Seashells.’
(Dover Publications: New York, USA.)
Webb, W. F. (1935). ‘A Handbook for Shell Collectors; Illustrations
and Descriptions of 1100 Species of Mollusca,’ 2nd ed. (Privately
published: Rochester, NY, USA.)
Webb, W. F. (1945). ‘Handbook for Shell Collectors; Illustrations and
Descriptions of Shells from All Parts of the World,’ 6th ed.
(Privately published: Rochester, NY, USA.)
Webb, W. F. (1951). ‘United States Mollusca; a Descriptive Manual of
many of the Marine, Land and Fresh Water Shells of North
America, North of Mexico.’ (Privately published: St. Petersburg,
FL, USA.)
Wheatley, C. M. (1842). ‘Catalogue of the Shells of the United States,
with Their Localities.’ (Privately published: New York, USA.)
Wheatley, C. M. (1845). ‘Catalogue of the Shells of the United States,
with Their Localities (Second Edition). ‘ (Privately published: New
York, USA.)
Wilkins, G. L. (1957). Notes on the Historiae Conchyliorum of Martin
Lister (1638–1712). Journal of the Society for the Bibliography of
Natural History 3(4), 196–205.
Willan, R. C. (1983). ‘Progressive Studies on the Taxonomy of
Australian Bivalves: the Family Limidae (File Shells). (Privately
distributed.) [Copy deposited in molluscan library at AMNH.]
Williams, P. (1992). Why they live where they live. American Conch-
ologist 20(1), 12–13.
Williams, W. (1988). ‘Florida’s Fabulous Seashells and Other Seashore
Life,’ 2nd ed. (World Publications: Tampa, FL, USA.)
Williams, W., and Carmichael, P. (1997). ‘Florida’s Fabulous Seashells
and Other Seashore Life,’ 6th ed. (World Publications: Tampa, FL,
USA.)
Winckworth, R. (1930). ) Notes on nomenclature. 6. Lima and allied
genera. Proceedings of the Malacological Society of London 19(3),
115–116.
Wood, W. (1828). ‘Index Testaceologicus; or a Catalogue of Shells,
British and Foreign, Arranged to the Linnean System; With the
Latin and English Names, References to Figures, and Places Where
Found,’ 2nd ed., corrected and revised. (W. Wood: London, UK.)
Woods, E. (1971). Grassy Key enclosure – gone! Seafari 13(1), 1–2.
Work, R. C. (1969). Systematics, ecology, and distribution of the
mollusks of Los Roques, Venezuela. Bulletin of Marine Science
19(3), 614–711.
Wye, K. R. (1991). ‘The Encyclopedia of Shells.’ (Knickerbocker
Press: New York, USA.)
Yonge, C. M. (1953). The monomyarian condition in the Lamelli-
branchia. Transactions of the Royal Society of Edinburgh 62(2),
443–478.
Zeiller, W. (1974). ‘Tropical Marine Invertebrates of Southern Florida
and the Bahama Islands.’ (John Wiley and Sons: New York, USA.)
Manuscript received 4 March 2003; revised and accepted 3 September
2003.