CUBAN SUBFAMILY CHONDROPOMINAE — TORRE AND BARTSCH 355 



turns very pale brown, the rest horn-color, unicolor or marked with 

 interrupted spiral bands of brown. These bands when present are 

 usually more strongly developed on the early turns than on the later, 

 and are present on both spire and base. The interior of aperture pale 

 buff; peristome yellowish horn-color. The whorls are strongly 

 rounded, narrowly shouldered at the summit, which is rendered feebly 

 crenulated by the occasional thickening of a rib. The axial sculp- 

 ture consists of very distantly sj^aced, feeble threads, the rest being 

 reduced to mere indications of feeble nodules at the summit and in- 

 cremental lines. The spiral sculpture consists of rather strong cords, 

 which are separated by spaces two to four times as wide as the cords. 

 Near the base and on the base the incremental lines become a little 

 stronger and slightly reticulate the spaces between the spiral cords. 

 Suture narrowly channeled. Periphery inflated, very strongly 

 rounded. Base inflated, w^ell rounded, narrowdy openly umbilicated, 

 marked by the same type of sculpture as that which characterizes 

 the spire, except in the umbilicus, where the spiral threads become in- 

 tensified. Aperture ovate; peristome double, the outer narrowly 

 expanded and reflected and rather thickened, adnate to the preceding 

 turn on the parietal wall, the inner also expanded and reflected and 

 projecting a little above the outer. Operculum thin, horny, pauci- 

 spiral, with the nucleus almost submarginal, covered on the outside 

 with a moderately thick, rather coarsely granular calcareous deposit. 

 The type, U.S.N.M. no. 493187, was collected on the Tomas Barrera 

 Expedition at Cape San Antonio. It has a little over 3 whorls and 

 measures: Length, 18.7 mm; greater diameter, 12.2 mm; lesser 

 diameter, 10.4 mm. 



CHONDROPOMA (CHONDROPOMA) MARGINALBUM (Gundlach) Pfeififer 



Truncated shell elongate-ovate, pale brown, with faint interrupted 

 spiral bands of brown ; peristome white, interior of aperture pale 

 brown. Nuclear whorls almost 2, inflated, strongly rounded, form- 

 ing a somewhat truncated apex, the first smooth, the last showing 

 the beginning of tlie postnuclear sculpture. Postnuclear wliorls 

 somewhat inflated, marked by strong, closely spaced, slightly retrac- 

 tively slanting axial riblets which crenulate the narrow sunmiit of 

 the whorls. The spiral sculpture consists of spiral cords which are 

 considerably stronger than the axial riblets, the junction of tlie axial 

 riblets and spiral cords form elongated nodules, which have their 

 long axis parallel with the axial sculpture. Suture narrowly chan- 

 neled. Periphery well rounded. Base moderately long, inflated, 

 well rounded, narrowly openly umbilicated, marked by the continu- 

 ation of the axial riblets and spiral threads with several fine spiral 

 threads on the umbilical wall. Aperture oval; peristome double, 



