350 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 85 



CHONDROPOMA (CHONDROPOMA) OBESUM (Menke) 



Shell elongate-conic when complete or elongate-ovate when trun- 

 cated, varying in color from gray to orange, white or pale yellow. 

 Nuclear whorls almost 2, forming a blunt apex, the first smooth, 

 the last with indications of the postnuclear sculpture. Postnuclear 

 whorls inflated, strongly rounded, almost appressed at the summit, 

 marked by slender, retractively curved, axial threads and spiral 

 lirations, the latter a little stronger than the axial threads. The 

 junctions of the two form slender nodules. Suture strongh' con- 

 stricted. Periphery strongly rounded. Base short, inflated, well 

 rounded, openly umbilicate, and marked like the spire. The last 

 whorl appressed to the preceding turn. Aperture broadly oval; 

 peristome double, the outer best shown at the posterior auricle and 

 on the inner lip, the inner peristome is coextensive with the outer. 

 Operculum paucispiral with submarginal nucleus, the outside 

 covered with a thin deposit of fine calcareous granules. 



This is a coastwise species and extends from Boca de Camarioca, 

 east of Matanzas, west to Boca de Jaruco, breaking up into four 

 subspecies. 



KEY TO THE SUBSPECIES OF CHONDROPOMA (CHONDROPOMA) OBESUM 



Diameter of shell more than 9 mm. 



Shell pale orange obesum 



Shell dark orange . subobesum 



Diameter of shell less than 7.5 mm. 



Shell gray . palmasolense 



Shell pale orange , hershei 



CHONDROPOMA (CHONDROPOMA) OBESUM PALMASOLENSE, new subspecies 



Plate 32, Figube 10 



This race occupies the region about Palmasola near Boca de 

 Camarioca, which lies halfway between Matanzas and Cardinas. 

 Shell gray and much smaller and more cylindrical when truncated 

 than the others. In this respect it resembles C. {C.) ohesum hershei^ 

 difi'ering from this, however, in coloration. 



The type, U.S.N.M. no. 468971, has 4 whorls remaining and meas- 

 ures: Length, 12.7 mm; greater diameter, 7.4 mm; lesser diameter, 

 6.2 mm. 



CHONDROPOMA (CHONDROPOMA) OBESUM SUBOBESUM, new subspecies 



Plate 32, Figure 9 



This race occupies the shoreline west of Matanzas but centers about 

 Punta de Sabanilla. It differs from C. (C.) ohesum ohesum in 

 being much darker orange and a little finer sculptured. 



