Notes on Drymaeus species from Peru (Mollusca, Gastropoda, Bulimulidae), and description of a new species

Abstract

Critical remarks are made on Drymaeus species, reported from Peru in a study on land snails from National Parks at the eastern side of the Andes. Four of these species (Dry­ maeus multilineatus, D. coniformis, D. glaucostomus, all known from Venezuela or Central America, and D. geomet­ ricus, known from Colombia) appear to be misidentified as Peruvian species, which thus may lead to incorrect biogeo- graphical interpretations. Correct identifications are given for all the disputed Drymaeus species. Bulimulus (Bulimu­ lus) inconspicuus F. Haas, 1949, is now transferred to Dry­ maeus (Mesembrinus). Additionaly, a new species, Drymae­ us (Drymaeus) verecundus Breure & Mogollón, is described.

Full text

  (-): 
Critical remarks are made on Drymaeus species, reported
from Peru in a study on land snails from National Parks at
the eastern side of the Andes. Four of these species (Dry-
maeus multilineatus, D. coniformis, D. glaucostomus, all
known from Venezuela or Central America, and D. geomet-
ricus, known from Colombia) appear to be misidentied as
Peruvian species, which thus may lead to incorrect biogeo-
graphical interpretations. Correct identications are given
for all the disputed Drymaeus species. Bulimulus (Bulimu-
lus) inconspicuus F. Haas, , is now transferred to Dry-
maeus (Mesembrinus). Additionaly, a new species, Drymae-
us (Drymaeus) verecundus Breure & Mogollón, is described.
Key words: biogeography, taxonomy, land snails, misiden-
tications, Peru.
INTRODUCTION
e Peruvian land snail fauna is known to be very species
rich, the number of species totalling  in a recent listing
(Ramírez et al., ). Since then, several more new taxa
have been described from this country (e.g., Breure, ;
Breure & Mogollón, , ; Miquel & Ramírez, ;
Borda & Ramírez, , ). A ‘grey literature’ publication
(Guevara,  []), i.e. a dissertation from Hamburg
University, dealt with the taxonomy of land molluscs col-
lected in and around three National Parks in eastern Peru.
Snails were collected in the vicinity of Moyobamba (Bos-
que de Alto Mayo), Tingo Maria (Parque Nacional Tingo
Maria), and Cuzco (Parque Nacional Manu). In total 
specimens were collected, belonging to  families and 
species. e thesis gives more details for the families Helici-
nidae (ten species, three of which new to science), Ceresidae
(three species) and Bulimulidae (nine Drymaeus species).
Of these nine bulimulid species, four were considered new
to the Peruvian malacofauna: Drymaeus multilineatus,
D. coniformis, D. glaucostomus, hitherto all known from
Venezuela or Central America, and D. geometricus, hith-
erto only known from Colombia. Although we have strong
doubts on some of the other identications, we will focus
on a critical review of the new records for the Peruvian ma l-
acofauna. Also we describe a new species of Drymaeus from
northeastern Peru and transfer a Bulimulus species to this
genus.
METHODS
e following abbreviations are used for the deposito-
ries of material: , Field Museum of Natural History,
Chicago, ...; , Instituto y Fundación Miguel Lillo,
Tucumán, Argentina; , Natural History Museum,
London, U.K.; , Royal Belgian Institute of Natural
Sciences, Brussels, Belgium; , Naturalis Biodiversity
Center, Leiden, e Netherlands; , private collection of
V. Mogollón, Lima, Peru; , Museum für Naturkunde,
Humboldt Universität, Berlin, Germany; , Zoologis-
ches Museum, Universität Hamburg, Hamburg, Germany.
RESU LTS
Drymaeus species supposedly new to the Peruvian
malacofauna
Of the nine Drymaeus species mentioned in the survey
of Guevara (), ve were either described from or are
Notes on Drymaeus species from Peru (Mollusca, Gastropoda,
Bulimulidae), and description of a new species
V M A
Universidad Nacional Federico Villarreal, Facultad de Oceanografía, Pesquería, Ciencias Alimentarias y Acuicultura, Roma ,
Lima , Perú
A S.H. B
Royal Belgian Institute of Natura l Sciences, Vautierstraat ,  Brussels, Belgium;
Naturalis Biodiversity Centre, P.O. Box ,   Leiden, e Net herlands; ashbreure@protonmail.com [corresponding author]
M A, V.  B , A.S.H., . Note s
on Drymaeus species from Peru (Mollusca, Gastro-
poda, Bulimulidae), and description of a new spe-
cies. – Basteria  (-): -. Leiden.
Published 6 April 2019

  (-):  
V. M A  A.S.H. B – Peruvian Drymaeus species
(L. Pfeier, ), and D. conformis (L. Pfeier, ).
Drymaeus multilineatus (Say, ) was reported from
Dept. San Martín, Cataratas del Gera near Moyobamba,
with two specimens (dimensions are given as  and  mm
for height, and  and . whorls). e specimen illustrated
(a broken shell) makes nevertheless clear that this species,
known to occur in Peru: D. eurystomus (Philippi, ), D.
expansus (L. Pfeier, ), D. peelii (Reeve, ), D. pul-
cherrimus (H. Adams, ), and D. strigatus (Sowerby,
). Four other species mentioned in Guevara () were
supposedly new to the Peruvian fauna: D. multilineatus
(Say, ), D. glaucostomus (Albers, ), D. geometricus
Figs 1-2. Comparison of ‘Drymaeus multilineatus’ sensu Guevara (: gs .-.;  ) [1a-c] with a syntype of Drymaeus
rectilineatus (L. Pfeier, ),   [2a-c]. Scale line  mm. Note that Guevara’s photos have been repositioned to make them
better comparable.
Figs 3-6. C ompar ison of ‘Drymaeus glaucostomus’ sensu Gueva ra (: gs .-.;   ) [3a-d] wit h the lectotype of Drymaeus
arcuatostriatus (L. Pfeier, ),   [4a-c]; and of ‘Drymaeus geometricus’ sensu Guevara (: gs .-.;  )
[5a-d] with the holotype of Drymaeus expansus scitus (H. Adams, ),  .. . [6a-c]. Scale line  cm. Note that Guevara’s
photos have been repositioned to make them better comparable.

  (-): 
V. M A  A.S.H. B – Peruvian Drymaeus species
Maria), scitus H. Adams,  (type locality “Eastern
Peru”), and arcuatostriatus L. Pfeier,  (from “Peru”);
see Pilsbry, -; Neubert & Janssen, ; Breure &
Mogollón, ; Breure, ; Breure & Ablett, . Taking
into account the locality where the material was collected,
and comparing Guevara’s gures with those of the papers
mentioned, we conclude that the specimen regarded by
her as D. glaucostomus (Figs a-d) is closely related to Dry-
maeus (D.) arcuatostriatus (L. Pfeier, ) (Figs a-c). e
latter species is somewhat smaller but belongs undoubtedly
to the same Drymaeus expansus species complex.
Drymaeus geometricus (L. Pfeier, ) was described
from the Magdalena valley in northern Colombia. So far
it was only known from that country. Guevara (: -
; our Fig. a-d) collected the material identied by her as
this species at Dept. Huánuco, Catarata la Quinceañera, 
km SE Tingo Maria,  m; it includes ten specimens with
an average shell height of . mm and . whorls. In our
opinion, this material also should be regarded as a form
of D. expansus (L. Pfeier, ). Guevara’s specimen (her
g. .; our Fig. a) respectively her g. . [our Fig. d]
closely resembles the comparable views of D. expansus sci-
tus (H. Adams, ) (our Figs a-c) from the same general
area. We also compared Guevara’s photos to the material of
D. expansus avilabrum Weyrauch, ; the latter shows
also similarities but this is a larger taxon.
Drymaeus coniformis (L. Pfeier, ) (incorrectly men-
tioned as “Pfeier, ” in Guevara, ) was described
from “Merida, Andes of Bolivia”, which Breure (: )
corrected to Venezuela. Guevara collected her material at
six localities in the vicinity of Tingo Maria (Guevara, :
which occurs in Florida and has also been reported from
coastal areas in Central America and Venezuela, has been
confused with a Peruvian species. We compared the gure
of Guevara with photos from type material in the Natural
History Museum, London (see Figs a-c versus a-c), and
found that this shell is a specimen of Drymaeus rectilinea-
tus (L. Pfeier, ); this species is known from the same
region having its type locality as “Meobamba” [= Moyo-
bamba].
Drymaeus glaucostomus (Albers, ) was described
from Venezuela and a subspecies has been described
from Suriname by Breure (), Drymaeus glaucostomus
meesi, which was considered a separate species by Mas-
semin et al. (). e lectotype of Albers’ species is 
 (Köhler, : , g. ). e material identied by
Guevara () as D. glaucostomus was collected at Dept.
San Martín, Cueva Pequeña,  km  Moyobamba, 
m, as a single shell with shell height  mm and  whorls.
Her g. . (Guevara, : ) shows a characteristic
bend in the columellar margin of the lip; in the description
longitudinal threads on the shell surface are mentioned. A
careful comparison with the known Peruvian taxa, leads us
to believe that this shell belongs to D. expansus (L. Pfeier,
). e typical form was described by Pfeier from
Huallaga, which is in the same general region. However,
D. expansus belongs to a species complex including other
taxa occurring in Peru which have been either regarded as
varieties, subspecies or separate species. ese taxa include
among others altorum Weyrauch,  (Chanchamayo),
aurisratti Philippi,  (Tarapoto), branneri F. Baker, 
(Puerto Maldonado), avilabrum Weyrauch,  (Tingo
Figs 7-10. Comparison of ‘Drymaeus coniformis’ sensu Guevara
(: g. .;  ,  a nd ) [7-9] wit h the holotype
of Drymaeus coelestini obesus Weyrauch, ,  (aer Breure,
 ) [10a-b]. Scale line  mm.
Fig. 11. Drymaeus (Mesembrinus) inconspicuus (F. Haas, ),
holotype  . Scale line  cm (a-c), . mm (d).

  (-): 
V. M A  A.S.H. B – Peruvian Drymaeus species
Drymaeus (Drymaeus) verecundus
Breure & Mogollón spec. nov.
(Figs -)
Diagnosis. — A small, fragile species of Drymaeus, up to
. mm height, with rather convex whorls, the last one .
times the shell height. Suture slightly ascending in front.
Aperture with a transparent-white, expanded and broad
lip, especially in its basal part.
Description. — Shell up to . mm height, . times
longer than wide, imperforate, the spire prole with rather
convex sides, rather elongated, thin. Colour pale bu to
greyish, with a pattern of one to three reddish-brown spiral
bands on the last whorl. Upper whorls in the same ground
colour as the rest of the shell. Surface dull to rather shin-
ing; the upper whorls smooth, on the remaining whorls the
growth striae slightly thickened, most noticeable on the last
whorl. Protoconch with a reticulate sculpture of axial rib-
lets and spiral striae, which are of equal strength. Whorls
., slightly convex, regularly rounded; suture slightly
impressed and bordered by a paler line below. Aperture
ovate, . times longer than wide, . times the total
length. Peristome slightly thickened, expanded, especially
-; Figs -); most of her material has an average shell
height of  mm and . whorls. e type material of D.
coniformis has not been located, but aer careful searching
and comparing, we come to the conclusion that this mate-
rial has also been misidentied and represents the similar
sized Drymaeus coelestini obesus Weyrauch,  (Fig. ).
Weyrauch’s material was collected at Boquerón del Padre
Abad, near Tingo Maria, and the holotype was re-gured
by Breure ().
Further notes on Peruvian Drymaeus
 While sorting gures we noticed that Bulimulus (Buli-
mulus) inconspicuus F. Haas,  is actually a Drymaeus
species as evidenced by the reticulate sculpture, with
equally strong axial and spiral elements, of the proto-
conch (Fig. d). is species was described from Peru,
Dept. Loreto, Río Ucayali, Contamana; the holotype is
  (Fig. a-c). e current status is Drymaeus
(Mesembrinus) inconspicuus (F. Haas, ) comb. nov.
 During research in Dept. Loreto, around Iquitos, a new
species of Drymaeus was collected, which we describe
here.
Figs 12-15. Drymaeus (D.) verecundus Breure & Mogollón spec. nov. 12a-c, holotype,  . . 13, paratype  . Scale line
 mm. 14, top view of juvenile paraty pe, with arrow to indicate the transition between proto- and teleoconch. Sca le . mm. 15a-b, living
paratype specimen.

  (-): 
V. M A  A.S.H. B – Peruvian Drymaeus species
studying the source material. e occurrence of these mis-
interpreted species in or around national parks may also
lead to the risk of their names being mentioned in studies
related to conservation issues. erefore it should be clear
that these four disputed taxa mentioned in the Guevara
study do not occur in the Peruvian malacofauna.
e nding of a new species in the immediate vicinity of
the city of Iquitos alerts us that even well-known areas may
still harbour novelties in the Neotropical malacofauna.
ACKNOWLEDGEMENTS
e rst author likes to thank Oswaldo Alva Marina for
his help in the eld. We are most grateful to Eugenia Salas
Oroño (Tucumán) for providing us with new photographs
of the type material of Drymaeus expansus avilabrum
Weyrauch, . e photographs of the  material
have been made by the sta of their Photo Unit (P. Crabb, P.
Hurst, H. Taylor), which is here thankfully acknowledged.
We are grateful to Dai Herbert and an anonymous reviewer
for their comments on the rst dra which helped to im-
prove the manuscript.
REFERENCES
B, V.  R, R., . Re-characterization of the
red-lip Megalobulimus (Gastropoda: Strophocheilidae)
from Peru with description of a new species. — Zoologia
 (): -.
B, V.  R, R., . e genus Megalobuli-
mus (Gastropoda: Strophocheilidae) from Peruvian
below. Columellar margin curved, reexed, receding. Pari-
etal wall with a very thin, transparent callus.
Type material. — Peru, Dept. Loreto, Iquitos, Quisto-
cocha,  m, -. W, -. S, V. Mogollón leg.,
.i.. Holotype   .; paratypes  .
(), . ( juvenile), .. ();   (
+  juv.). Measurements of the material are given in Table .
Remarks. — is new taxon resembles Drymaeus (D.)
rosenbergi S.I. Da Costa, , from Pozuzo, from which it
diers by () being slightly smaller; () having the aperture
regularly rounded at base; and () having a dierent col-
our pattern. From D. (D.) castaneostrigatus S.I. Da Costa,
, described from the same locality, it diers in () being
slightly smaller; () more fragile; () having a less expanded
peristome. It may also be compared to Drymaeus (Mesem-
brinus) rectilinearis (L. Pfeier, ), from Moyobamba,
in having a similar colour pattern, but diers in () being
smaller; () more fragile; () having more convex whorls;
and () a more expanded peristome at base.
Etymology. — (L.) verecundus, modest. Epithet chosen to
mark the relative small size among its congeners.
DISCUSSION
If a species is recorded in a region not mentioned in the
literature and relatively far from which it was originally
described, a taxonomist should always become suspicious.
Is it likely to be the supposed taxon, or rather a species of
similar appearance? Accurate identication is key to biodi-
versity science. Misidentications hamper the study of bio-
geography as incorrect names may also turn up in online
databases, which may e.g. be used for meta-studies without
Table 1. Measurements in Drymaeus (D.) verecundus Breure & Mogollón sp.n. i rd paratype i n  collection par tly damaged, making
comparable measurements impossible. Abbreviations: , shell diameter; , shel l height; , height of aperture; , last whorl; , number
of whorls; , width of aperture.
H D HA WA LW W
17.7 8.95 8.24 5.40 12.0 6.2 holotype
17.9 9.07 8.71 5.62 12.8 6.0 
16.6 9.43 9.19 4.84 11.9 4.9 
16.5 9.6 8.70 5.44 12.0 5.1 
18.7 9. 68 8.95 5.21 12.9 6.2 
18.2 9.65 8.35 5.22 12.5 6.1 
16.9 8.54 8.63 5.20 12 .1 5.7 
17. 3 9.56 8.61 5.51 11.9 5.8 
17. 5 5.7 

  (-): 
V. M A  A.S.H. B – Peruvian Drymaeus species
(Gastropoda: Pulmonata: Bulimulidae), en tres zonas de
la Reserva Amazónica de Perú: i-xx, -. Diplomarbeit
Fachbereich Geowissenschaen der Universität Ham-
burg, Hamburg / Berlin [, unpublished] / Verlag im
Internet GmbH [].
K, F., . Annotated type catalogue of the Bulim-
ulidae (Pulmonata, Orthalicoidea, Bulimulidae) in
the Museum für Naturkunde Berlin. — Mitteilungen
Museum für Naturkunde Berlin, Zoologische Reihe 
(): -.
M, D., L, D., P, J.-P.  G,
O., . Coquillages et escargots de Guyane. Seashells
and snails from French Guiana: -. Biotope / Muséum
national d’Histoire naturelle, Mèze / Paris.
M, S.E.  R, R., . First records of actual
and fossil Stephadiscus outside Patagonia, and descrip-
tion of a new Amazonian species (Mollusca: Pulmonata:
Charopidae). — Archiv für Molluskenkunde  ():
-.
N, E.  J, R., . Die Typen und Typoide
des Natur-Museums Senckenberg, : Mollusca: Gastro-
poda: Pulmonata: Orthalicoidea: Bulimulidae (),
Orthalicidae, Placostylidae. — Archiv für Mollusken-
kunde  (-): -.
P, H.A., -. American Bulimulidae: Bulimu-
lus, Neopetraeus, Oxychona, and South American Dry-
maeus. — Manual of Conchology, Second series  ():
-, pls - ();  (): -, pls - ();  ():
-, pls - ();  (): -, pls , -
().
R, R., P, C.  A, J., . Molucos del
Perú. — Revista de Biología Tropical  (Supplemento ):
-.
Andes: Re-description of Megalobulimus leucostoma and
description of two new species. —American Malacolog-
ical Bulletin (): -.
B, A.S.H., . Notes on Bulimulidae (Gastropoda,
Euthyneura), . Some Bulimulidae from French Guyana
and Surinam, with notes on their anatomy. — Zoologi-
sche Mededelingen Leiden  (): -, pl. .
B, A.S.H., . Systematics, phylogeny and zooge-
ography of Bulimulinae (Mollusca). — Zoologische Ver-
handelingen Leiden : -, pls -.
B, A.S.H., . Carination strikes the eye: extreme
shell shapes and sibling species in three Andean genera
of the Orthalicidae (Gastropoda, Stylommatophora). —
Zoologische Mededelingen Leiden  (): -.
B, A.S.H., . Weyrauch’s type localities: a clari-
cation; with illustrations of types of Orthalicoidea (Mol-
lusca, Gastropoda, Stylommatophora) in the Tucumán
museum. — Folia Conchyliologica : -.
B, A.S.H.  A, J.D., . Annotated type
catalogue of the Bulimulidae (Mollusca, Gastropoda,
Orthalicoidea) in the Natural History Museum, London.
— ZooKeys : -.
B, A.S.H.  M, V., . Well-known and
little-known: miscellaneous notes on Peruvian Orthali-
cidae (Gastropoda, Stylommatophora). — Zoologische
Mededelingen Leiden  (): -.
B, A.S.H.  M, V., . Synopsis of Cen-
tral Andean Orthalicoid land snails (Gastropoda, Sty-
lommatophora), excluding Bulimulidae. — ZooKeys :
-.
G, S., []/. Estudio taxonómico y sys-
temático de las familias Helicinidae y Ceresidae (Mol-
lusca: Gastropoda: Neritopsina) y el género Drymaeus