Some Mexican Land Snails of the Family Urocoptidae

Abstract

The genus Anisospira Strebel, 1880 is redefined on the basis of anatomical characters and divided into two subgenera. Anisospira (sensu strictu) is restricted to include only the species from the Tehuantepec region. Trachycion n. subgen., is proposed to include the remaining western Mexican species formerly placed in Anisospira (s.s.). Dissotropis Bartsch, 1906 is redefined anatomically, removed from subgeneric status within Anisospira, and recognized as a distinct genus more closely related to Coelocentrum.

A. -liebmanni (Pfeiffer) and A. dalli (Martens) are redefined, and their anatomies are described for the first time. Cylindrella hyalina Pfeiffer, A. orcutti Dall, and Liocentrum wilmoti Bartsch are synonymized with A. liebmanni. New subspecies and species include: A. d. strigens n. ssp. from near Tehuantepec, A. (T.) hadromylla n. sp. from Coastal Michoacan, D. castaneum n. sp. from Jalisco, and D. amplaxis n. sp. from Colima. The anatomy of D. castaneum is described, providing a basis for relating Dissotropis to Coelocentrum.

Also included are the descriptions of the following: Coelocentrum tanydeira n. sp. from San Luis Potosi; C. stenocion n. sp. from Guerrero; and C. tomacella adelphion n. ssp., C. tyla n. sp., C. cataclines n. sp., and Eucolodium otoides n. sp. all from Chiapas. Coelocentrum nelsoni Dall is redescribed and its type locality restricted. The embryonic shells of C. pfefferi Dall, C. turris (Pfeiffer), C. tomacella clava (Pfeiffer), and Eucolodium hegewischi Bartsch are also described. Crossostephanus Dall, 1908 is synonymized with the subgenus Coelocentrum Crosse and Fischer, 1872. Cylindrella ghiesbreghti (Pfeiffer), 1856 is synonymized with Eucolodium decollatum (Nyst), 1841.