212 BULLETIN 192, UNITED STATES NATIONAL MUSEUM 



The postnuclear whorls are quite strongly rounded and marked by low 

 spiral threads, which are a little narrower than the spaces that separate 

 them. These cords are crossed by numerous closely spaced, almost ob- 

 solete hairlines, which, however, are not strong enough to render the 

 spiral threads nodulose. Suture moderately constricted, channeled for 

 about one-tenth of a turn behind the aperture. The summit of the whorls 

 is very finely nodulose. Periphery of the last whorl inflated, strongly 

 rounded. Base moderately long, openly umbilicated, and marked by the 

 continuation of the same type of sculpture as that which characterizes 

 the spire. There are fine spiral threads also in the umbilicus. Aperture 

 very broadly ovate, moderately auriculated at the posterior angle. The 

 parietal wall does not quite touch the preceding turn; it therefore leaves 

 the last whorl slightly solute. Peristome double; the outer and inner 

 fused, being differentiated only at the posterior angle. Operculum typi- 

 cally chondropomoid. 



This species appears to range through the Turks Island group where 

 I am recognizing several races, which the following key will help to dis- 

 tinguish : 



KEY TO THE SUBSPECIES OF CHONDROPOMA (CHONDROPOMA) HJALMARSONI 



Color marking strong saliniun 



Color marking not strong. 



Granules at summit strong gossypinum 



Granules at summit feeble hjalmarsoni 



CHONDROPOMA (CHONDKOPOMA) HJAL,MARSONI SALINCM, new subspecies 



Plate 35, Figure 2 



This race comes from Salt Cay. In this the spiral color bands are very 

 broad and the shell is much larger than the other two races and more 

 elongate. 



The type (U.S.N.M. No. 469142), collected by Bartsch, has 3.5 whorls 

 remaining and measures: Length, 15.9 mm.; greater diameter, 9.9 mm.; 

 lesser diameter, 7.8 mm. 



U.S.N.M. No. 391863 contains 89 topotypes from the same source. 



U.S.N.M. No. 391856 contains i specimen collected by Bartsch at 

 the south end of Salt Cay. 



CHONDROPOMA (CHONDROPOMA) HJALMARSONI GOSSYPINUM, new subspecies 



Plate 35, Figure 1 



This subspecies comes from Cotton Island. It is characterized by 

 having the color markings pale and the denticulation at the summit quite 

 strong. In size it agrees fairly well with the typical race. 



The type (U.S.N.M. No. 469148) has 3.2 whorls remaining and 

 measures: Length, 13.0 mm.; greater diameter, 8.5 mm.; lesser diame- 

 ter, 7.0 mm. It was collected by Bartsch. 



U.S.N.M. No. 390834 contains 22 topotypes from the same source. 



