COGHLOSTYLA OF MINDORO PROVINCE 435 



Shell broadly conic, covered by a thin periostracum, which varies 

 from grayish brown to wood brown. When the periostracum is 

 removed from the earlier turns, they are shown to be flesh color or 

 flesh color with a pinkish brown tint, the succeeding turns becoming 

 gradually darker until the last one is bright chestnut-brown between 

 the periphery and summit and bright dark chestnut-brown on the 

 base. The interior of the aperture is bluish white, and the peristome 

 is edged with brown ; the columella has a pinkish cast. Nuclear whorls 

 1.5, well rounded, marked only by lines of growth. The postnuclear 

 turns are moderately rounded, appressed at the summit, and marked 

 by retractively slanting lines of growth, which are a little stronger 

 on the last turn than on the early whorls, and also by microscopic 

 closely crowded spiral striations, which are present on both spire and 

 base. Suture moderately constricted; periphery of the last whorl 

 obsoletely angulated. The base is short, somewhat inflated, and 

 strongly rounded. The aperture is almost circular, oblique; outer lip 

 slightly expanded and reflected. The columella is moderately broad, 

 slightly excavated, and reflected at its insertion over the base, and the 

 parietal wall has a moderately thick callus. 



The type (U.S.N.M. no. 313637) was collected by Pedro de Mesa 

 on Mount Sapol, Calapan, Mindoro. It has 5.7 whorls and measures: 

 Length, 50.3 mm; greater diameter, 39.2 mm; lesser diameter, 34 mm. 



Two topotypes (U.S.N.M. no. 313638), from the same source, 

 yield, respectively, the following measurements: 5.7 whorls each; 

 length, 52.3 and 51.8 mm; greater diameter, 39.5 and 40 mm; lesser 

 diameter, 34.7 mm each. 



This species belongs to the group of Cochlostyla (Orthostylus) pitho- 

 gaster, not treated in this paper. It is a group much in need of revision, 

 for the name Cochlostyla pithogaster has been used as a catch-all. 

 In order thoroughly to understand its relationship to the other mem- 

 bers of the group, it would be necessary to revise the group, which is 

 not within the province of the present paper. 



Subgenus Hypselostyla Martens 



In this subgenus the shell is elongate-ovate to conic, imperforate, 

 with more or less keeled periphery, and covered with a thin hydroph- 

 anous periostracum. The aperture is oval to subquadrate, and the 

 peristome is but slightly expanded and reflected. 



Since no type appears to have been definitely designated for the 

 group, I now select Cochlostyla (Hypselostyla) nympha (Pfeiffer), one 

 of the two species mentioned by von Martens. 



COCHLOSTYLA (HYPSELOSTYLA) CINCINNIFORMIS (Sowerby) 



Shell ovate-conic, usually rather thin, never ponderous, covered 

 with a thin periostracum, which in the various races varies from pale 



