26 BULLETIN 192, UNITED STATES NATIONAL MUSEUM 



slender riblets, plus a lot of fine ribs immediately behind the lip. These 

 riblets extend strongly to the summit of the whorls where they become 

 slightly intensified, thus rendering the shoulder at the summit crenulated. 

 Suture somewhat channeled. Periphery of the last whorl well rounded. 

 Base narrowly openly umbilicated, well rounded, marked by the con- 

 tinuations of the axial riblets, which become a little weaker and a little 

 more closely crowded toward the umbilicus ; the umbilical wall is marked 

 by slender spiral cords. The last third of the last turn is solute. The out- 

 side of the parietal wall is marked by obsolete continuations of the 

 axial riblets. The summit of the last whorl on the solute portion forms 

 an acute crenulated carina. Aperture oval; peristome slightly expanded 

 and reflected all around. Operculum paucispiral, with excentric nucleus, 

 the outer edge upturned, the last whorl covered with a rather strong 

 deposit of fine calcareous granules. 



KEY TO THE SUBSPECIES OF CHONDROPOMA (CHONDROPOMIUM) SWIFTII 



Shell with spiral bands of brown. 

 Spiral bands continuous. 



Dark spiral bands as broad as or broader than intervals 



that separate them saturatum 



Dark spiral bands not so broad as intervals that separate 



them barahonense 



Spiral bands interrupted. 



Ground color of shell flesh-colored weinlandi 



Ground color of shell buff swiftii 



Shell without spiral bands of brown azuense 



CHONDROPOMA (CHONDROPOMIUM) SWIFTII SATURATUM, new subspecies 



Plate 4, Figure 4 



1846. Cyclostoma semilahre Pfeiffer, Martini-Chemnitz Conchylien Cabinet, ed. 

 2, vol. 1, sect. 19, pi. 49, fig. 18 ( ?). 



This is a small race with very dark, broad, brown spiral bands upon 

 a pale buff background, the bands being broader than the intervals that 

 separate them. In some shells these bands become almost fused and give 

 the shell a completely brown aspect. It is of the size of Chondropoma 

 (Chondropomhim) swiftii swiftii and differs from that in being more 

 cylindric, much more closely ribbed and in having the last whorl less 

 solute. 



The type (U.S.N.M. No. 493299) comes from the Cuining Collection, 

 which means that it is of Salle's collecting. It has 3.9 whorls remaining 

 and measures : Length, 16.6 mm. ; greater diameter, 8.8 mm. ; lesser 

 diameter, 7.8 mm. 



U.S.N.M. No. 354953 contains a paratype from the same source. 



CHONDROPOMA (CHONDROPOMIUM) SWIFTII BARAHON£NSi; new subspecies 



Plate 4, Figure 3 



This race was collected by W. L. Abbott at Barahona. The truncated 

 shell is narrowly oval, the spiral bands are continuous, and though con- 



