202 BULLETIN 192, UNITED STATES NATIONAL MUSEUM 



CHONDBOPOMA (CHONDBOPOanSCA) SACCHABINETEN8E, new species 



Plate 32, Figure 3 



Shell of pupoid outline, pale straw-colored, marked with interrupted 

 spiral bands of brown; the elements composing these also fall in axial 

 series. Nuclear whorls about 2, inflated, strongly rounded, smooth. Post- 

 nuclear whorls rather strongly rounded and marked by slender, almost 

 vertical axial riblets, which are rendered denticulate by the spiral threads. 

 These riblets extend to the summit where they form rather sharp cusps. 

 Of these, 24 are present on the first, about 30 upon the second, and 32 

 upon the last of the remaining turns. Suture moderately impressed. Pe- 

 riphery well rounded. Base short, strongly rounded, and marked by the 

 continuation of the axial ribs and spiral cords, which produce the same 

 type of sculpture on the riblets as on the spire. Last whorl solute for 

 about one-sixth of a turn. Aperture very broadly ovate, almost sub- 

 circular, slightly expanded and reflected at the edge, where it is some- 

 what thickened. 



The type (U.S.N. M. No. 536740) and a large series of specimens I 

 collected on Sugar Loaf Cay southeast of Providenciales. The type has 



3.6 whorls remaining and measures : Length, 8.3 mm. ; greater diameter, 



5.7 mm. ; lesser diameter, 4.6 mm. 



U.S.N.M. No. 391390 contains 56 topotypes from the same source. 



This species varies considerably in size, some specimens being much 

 larger than the type ; others smaller. A single dead specimen and a frag- 

 ment collected on the shores of the bay south of North Point on Little 

 Inagua do not show characters to differentiate them from the species 

 above described. 



Subgenus Chondropoma Pfeiflfer 



1847. Chondropoma Pfeiffer, Zeitschr. Malak., vol. 6, p. 109. 



Shell ranging in form from ovate-conic to elongate-conic. The axial 

 sculpture consists of ribs or riblets, which vary considerably in strength 

 in the different species. The riblets are never gathered into tufts at the 

 summit. The spiral sculpture is also quite variable, but regardless of 

 its strength it is found upon all parts of the spire and base. The peri- 

 stome may be simple or expanded. No breathing device is present. Oper- 

 culum typically chondropomoid. 



Type species: Cyclostoma sagra Orhigny= Chondropoma (Chon- 

 dropoma) pictum sagra (Orbigny). 



KEY TO THE BAHAMAN SPECIES OP THE SUBGENUS CHONDROPOMA 



Spire decidedly granulose. 



Whorls strongly rounded. 



Last whorl solute graniferum 



Last whorl not solute mariguanicolutn 



Whorls not strongly rounded pannosum 



