528 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



faint peripheral brownish zone. The parietal callus is also marked 

 with a dark edge. Nuclear whorls 3, the first smooth, the last show- 

 ing the sculpture of the postnuclear whorls. The postnuclear whorls 

 are appressed at the summit, moderately rounded, and rendered 

 rather rough by irregularly developed and somewhat irregularly spaced 

 retractively curved incremental threads, which on the last whorl ex- 

 tend to the umbilical region. They are also marked by poorly ex- 

 pressed, fine spiral striations and the usual fine microscopic crisscross 

 incised lines that cut the lines of growth at right angles. The aperture 

 is broadly oval; the peristome is decidedly expanded and reflected, 

 that of the inner lip being broadly expanded at its insertion where it is 

 reflected over the umbilicus, which it almost covers. The parietal 

 wall is covered by a rather thick callus. 



This species recalls strongly Cochlostyla (Chrysallis) caniceps, from 

 which it can at once be distinguished by its dark nuclear turns. So 

 far it is known from the eastern and southwestern coasts of Mindoro. 

 I am recognizing three races of it: Cochlostyla (Chrysallis) nigriceps 

 nigriceps, from the region of Lake Naujan; C. (C.) n. nubifer, from 

 southwestern Mindoro; and C. (C.) n. obnubila from Binuangan, 

 northwestern Mindoro. 



KEY TO THE SUBSPECIES OF COCHLOSTYLA (CHRYSALLIS) NIGRICEPS 



Ground color chocolate-brown. 



Greater diameter more than 30 mm nubifer 



Greater diameter less than 30 mm nigriceps 



Ground color blackish brown obnubila 



COCHLOSTYLA (CHRYSALLIS) NIGRICEPS NUBIFER Bartsch 



Plate 113, Figure 1 



1932. Cochlostyla (Chrysallis) nigriceps nubifer Bartsch, Journ. Washington Acad. 

 Sci., vol. 22, p. 343. 



Shell elongate-conic. All the nuclear whorls dark chocolate-brown. 

 The postnuclear whorls are chestnut-brown overlaid with a rather 

 thick periostracum, which is marked by fulgurations and cloudings of 

 soiled straw-color. The base is considerably darker than the space 

 between the summit and the periphery, the distinction between the 

 two being indicated by a sharp line. Interior of the aperture bluish 

 white; peristome chocolate-brown. The inner edge of the peristome 

 gradually fades into the color of the aperture. The inner portion of 

 the insertion of the columella is also light in tone, while the parietal 

 callus is dark-edged. Nuclear whorls almost 3, the first smooth, the 

 second one showing fine incremental lines, and the last one the rough 

 sculpture of the postnuclear turns. The postnuclear turns are slightly 

 rounded, appressed at the summit and marked by irregularly devel- 

 oped and spaced, retractively curved, threadlike incremental lines. In 



