14 BULLETIN 192, UNITED STATES NATIONAL MUSEUM 



The spaces enclosed between the axial riblets and spiral threads may be 

 fine pits or slightly quadrangular impressions. Both the axial and spiral 

 sculptures are well rounded, and their junction does not produce marked 

 tuberculation. The suture is impressed and rendered crenulated by the 

 denticles at the summit of the whorls. Periphery somewhat inflated, 

 well rounded. The base is moderately long, inflated, well rounded, very 

 broadly openly umbilicated, and marked like the spire but with the 

 sculpture a Httle less strong than that of the spire. On its outer half 

 the umbilical wall shows a number of spiral threads which are a little 

 stronger than those on the base. The last whorl is solute for one-fifth 

 of a turn. On the solute portion there is a decided carina following the 

 posterior angle of the aperture. The aperture is broadly oval; peristome 

 simple. 



I have seen this species from Monte Cristi and Santiago Provinces, 

 Dominican Republic. 



I am recognizing two subspecies, which the following key will help 

 to dififerentiate : 



KEY TO THE SUBSPECIES OF CHONDROPOMA (CHONDROPOMORUS) PILSBRTI 



Truncated shell subcylindric pilsbryi 



Truncated shell elongate-ovate nonuni 



CHONDROPOMA (CHONDROPOMORUS) PII.SBRYI PII.8BRYI, new subspecies 



Plate 1, Figure 6 



This race Dr. W. L. Abbott found abundantly at Guayubin Rio Yaque 

 del Norte, Monte Cristi Province, Dominican Republic. 



This is distinguished from Chondropoma (Chondropomorus) pilsbryi 

 nonuni by having the spire elongate-ovate and the v/horls a little more 

 inflated and much more finely denticulated at the summit. It is also of 

 darker coloration. 



The type (U.S.N.M. No. 515241) has 4.5 whorls remaining and 

 measures: Length, 16.2 mm.; greater diameter, 8.5 mm.; lesser diameter, 

 7.0 mm. 



U.S.N.M, No. 515242 contains 70 topotypes from the same source. 



CHONDROPOMA (CHONDROPOMORUS) PILSBRYI NONUNI, new subspecies 



Plate 1, Figure 7 



This subspecies was collected by Dr. W. L. Abbott above the Navar- 

 rete Station on the railway between Puerto Plata and Santiago, Santiago 

 Province, Dominican Republic. It is distinguished from Chondropoma 

 (Chondropomorus) pilsbryi pilsbryi in being more cylindric in shape, 

 of paler coloration, and in having the denticles at the summit much more 

 pronounced. 



The type (U.S.N.M. No. 515243) has 4.5 whorls remaining and meas- 

 ures: Height, 15.7 mm.; greater diameter, 7.8 mm.; lesser diameter, 

 6.3 mm. 



U.S.N.M. No. 515244 contains 12 topotypes from the same source. 



