BULIMULUS. 125 



Genus BULIMULUS Leach, 1815. 



Bulimulus LEACH, Zool. Miscellany, i, p. 41 (for B. acutvs and 

 B. trifasciatus Leach, = Helix exilis Gmel.)- v. MARTENS in Die 

 Binnenmoll. Venezuela's, p. 21 (1873) ; Biol. Amer. Cent., p. 238 

 (1895). SEMPER, Reisen in Archipel der Philippinen, Land-moll., 

 iii, p. 153. Bulimulus s. g. Orthotomium, FISCHER & CROSSE, Miss. 

 Sci. Mex. Moll, i, p. 473 (1875). 



Shell varying from ovate-conic to oblong, columnar or lanceolate ; 

 umbilicate or imperforate ; aperture with the lip thin, generally not 

 expanded ; columella expanded, rather straight, sometimes with a 

 callous fold within. Apical whorls either smooth, vertically costu- 

 late or wrinkled, or with the wrinkles interrupted and broken into 

 granules ; never sculptured with spiral and vertical raised strice form- 

 ing a minute grating. 



Radula substantially as in the normal, terrestrial HelicidaB. 



Jaw composed of rather few plates with vertical, narrowly free 

 lateral edges not sufficiently converging to form a triangular area of 

 shorter plates in the middle. 



Genitalia without accessory organs or appendages. 



Type Bulimulus exilis (Gmelin). 



DISTRIBUTION: Warm temperate and tropical America, from 

 Argentina and Chili north to Arkansas and Tennessee. No spe- 

 cies of Bulimulus occur in the Eastern Hemisphere, although sev- 

 eral genera, such as the Australian Liparu*, and Placostylus, a group 

 of the Melanesian tract, are closely allied to American genera. 



The species of Bulimulus live by preference on the ground or on 

 low herbage or shrubs. Hybernation or aestivation usually takes 

 place in the soil, but they sometimes sestivate on bushes during dry 

 weather. 



Bulimulus is here used in the sense in which it has been under- 

 stood by von Martens in his several references to the genus since 

 1873. This is a narrower meaning than the ordinary usage, and 

 practically equivalent to Orthotomium of Crosse and Fischer. It is 

 closely allied to DRYM/FAJS (= Otostomus Martens, not of Beck as 

 restricted by Gray and Herrmannseu), but differs in the Helicid 

 character of the teeth, and to a less extent in the fewer, wider, less 

 converging ribs of the jaw. The shells differ in the system of sculp- 

 ture of the apical whorls, which in Drymceus show a very fine grat- 

 ing formed by the intersection at right angles of vertical and spiral 



