Eucosma emaciatana (Walsingham) is transferred to Pelochrista Lederer, and Pelochrista perpropinqua (Heinrich) is recognized as a junior synonym of P. emaciatana. Three species considered by previous authors to be superficially similar to ema-ciatana are reviewed: Eucosma larana (Walsingham), Eucosma totana Kearfott and Pelochrista popana (Kearfott). Four previously unrecognized species are described: Eucosma piperata, new species, Eucosma nordini, new species, Eucosma taosana, new species, and Pelochrista powelli, new species. Lectotypes are designated for emaciatana and larana. Adults and genitalia of these species are illustrated, and new distributional records are presented. Additional key words: Oletreutinae, Pelochrista, Nearctic. The Rocky Mountain and Great Basin regions of western United States are home to many similar looking species of Eucosmini, some of which were named by Walsingham in the last quarter of the nineteenth century. Lacking access to the Walsingham types, early North American tortricid specialists often had difficulty applying those names, and in some instances the confusion that resulted has persisted to the present day. One such case involves Eucosma emaciatana (Walsingham), Eucosma larana (Walsingham), and Pelochrista perpropinqua (Heinrich). Heinrich (1923) confused emaciatana with larana (see discussion below) and later (1929) described perpropinqua based on a series of specimens of emaciatana. I confirmed that emaciatana and perpropinqua refer to a single taxon by examining the types. Based on male genitalia, the appropriate generic assignment for this species is Pelochrista Lederer, a conclusion reached by Powell (1983) in his placement of perpropinqua, so I propose to resolve this situation by transferring emaciatana to Pelochrista and treating perpropinqua as a junior synonym. In examining specimens from various institutional and private collections I encountered two previously unrecognized species of Eucosma Hübner that have been confused with larana. They are described below as E. piperata, new species, and E. nordini, new species. Also included are reviews of E. totana Kearfott and P. popana (Kearfott), two species considered by previous authors to be similar in appearance to larana and/or emaciatana. Finally, descriptions are provided for two additional new taxa, Eucosma taosana, new species, and Pelochrista powelli, new species. The former has previously been misidentified as totana; the latter is superficially similar to totana and taosana. Walsingham (1884) described Paedisca emaciatana from three male specimens collected by H. K. Morrison in Arizona. Fernald [1903] placed this species in Eucosma, and there it has resided ever since. The Fernald collection, acquired by the United States National Museum (USNM) in 1924-25, included two male specimens determined by Walsingham as emaciatana. Neither has an abdomen. One was collected by Morrison in Arizona in 1883 and agrees with the description of emaciatana, the other is lacking collection data and is in such poor condition that I cannot confirm the accuracy of its determination. Heinrich's review (1923) of emaciatana makes no mention of these two specimens, so I assume he did not examine them. His treatment was based on a series of specimens from Utah, and he illustrated the genitalia (Fig. 193) of a male collected by Tom Spalding at Eureka, Utah, on 27 July 1911. I examined that specimen and a number of other USNM specimens determined by Heinrich as emaciatana and concluded (see discussion below) that they represent E. larana. This explains why Heinrich, when presented with specimens of emaciatana collected in Arizona by O. C.