COCHLOSTYLA OF MINDORO PROVINCE 



415 



last portion by indications of fine spiral lines. The postnuclear 

 whorls are well rounded, somewhat inflated, and marked by re- 

 tractively curved lines of growth and microscopic spiral striations on 

 both spire and base. The periphery is well rounded. The base is 

 somewhat inflated and strongly rounded. The aperture is almost 

 circular, oblique. The peristome is moderately expanded and reflected. 

 The columella is rather narrow and excavated. 



The type (U.S.N.M. no. 313611) was collected by me on the hill 

 on the west shore of Mansalay Bay, Mindoro. It has 5.4 whorls and 

 measures: Length, 31.8 mm; greater diameter, 24.3 mm; lesser 

 diameter, 21.9 mm. 



A series of topotypes yields the following additional measurements: 



Two of the specimens have also a peripheral band, and one has a 

 band between that of the summit and the periphery. 



This race is distinguished from all the others by its exceedingly thin 

 shell and the curious pale coloration of the periostracum, which is of 

 an olivaceous-waxy color. 



In this as in other species I collected in Mansalay Bay we find a 

 distinction between those obtained on the west shore and those on the 

 east shore, the differentiation being a parallel one in all the instances. 



