392 BULLETIN 10 0, UNITED STATES NATIONAL MUSEUM 



The specimens yield the following measurements: 



This race is easily distinguished from the other dark-colored forms 

 by its smaller size. The dark Ilin Island shells are differentiated from 

 those of Mindoro by having the peristome of the outer lip paler, in 

 most instances white or merely edged with brown, while in the Mindoro 

 shells the outer lip is dark. 



COCHLOSTYLA (CALOCOCHLEA) ROISSYANA CAVITALA Bartsch 



Plate 96, Figures 10-12 



1932. Cochloslyla (Calocochlea) roissyana cavitala Bartsch, Journ. Washington 

 Acad. Sci., vol. 22, p. 336. 



Shell large, subglobular. The nuclear whorls when perfect are 

 covered with a thin olivaceous periostracum. The nuclear whorls 

 and the early postnuclear whorls are flesh-color, with a zone of black 

 near the summit and immediately posterior to the periphery. These 

 zones increase rapidly in size but always maintain between them a 

 broad band of flesh-color. A narrow zone of flesh-color is present on 

 the periphery and still another at the middle of the base. The latter 

 is frequently tinged with brown or reddish brown, the rest of the base 

 being like the bands of the spire, very dark brown. The aperture 

 is bluish white showing the dark bands within. The columella is 

 soiled white, while the outer lip is dark. 



