COCHLOSTYLA OF MINDOKO PROVINCE 497 



COCHLOSTYLA (CHRYSALLIS) ROSEOLABRA Bartsch 



Shell varying from elongate-conic to broadly ovate. The color 

 varies from yellowish buff to pale wood brown; the early whorls are 

 always lighter than the later ones. The interior of the aperture may 

 be bluish white or bluish white with a purplish tinge, and the peri- 

 stome may be pale rose-color or bright rose-color, varying with the 

 subspecies in question. The shell is covered with a thin periostracum, 

 which bears hydrophanous lines. These are most conspicuous near 

 the summit of the whorls, which they render falsely toothed. Nuclear 

 whorls almost 3, forming a blunt apex, marked by retractively curved 

 axial lines of growth, which are strongest on the last turn. Here 

 they assume almost the strength of those of the postnuclear whorls. 

 The postnuclear whorls are moderately well rounded, appressed at 

 the summit, marked in one of the races by rather strong, retractively 

 curved, incremental lines. In fact in this race they almost resemble 

 threads, while in the other this sculpture is decidedly reduced in 

 strength and the shell is almost smooth. The periphery of the last 

 whorl is feebly angulated. The base is rather inflated and strongly 

 rounded. The periphery is broadly oval; the peristome is expanded 

 and reflected. The inner lip also is reflected, the reflection forming a 

 narrow umbilicus. 



The species, as far as known at present, is confined to northwestern 

 Mindoro. I am recognizing two subspecies, but there is an indication 

 of still another one. 



KEY TO THE SUBSPECIES OF COCHLOSTYLA (CHRYSALLIS) ROSEOLABRA 



General color of shell yellowish buff roseolabra 



General color of shell wood brown rosea 



COCHLOSTYLA (CHRYSALLIS) ROSEOLABRA ROSEOLABRA Bartsch 



Plate 111, Figure 4 



1932. Cochlostyla (Chrysallis) roseolabra roseolabra Bartsch, Journ. Washington 

 Acad. Sci., vol. 22, p. 341. (June.) 



1932. Helicostyla chrysalidiformis calawaganensis Smith, Nautilus, vol. 46, p. 64, 



pi. 4, figs. 4, 6. (October.) 



1933. Helicostyla (Chrysallis) mindoroensis flavipellis Clench and Archer, 



Papers Michigan Acad. Sci., Arts, Letters, vol. 17, p. 548, pi. 18, fig. 5. 



The shell is ovate. The early whorls are pale buff, the later ones 

 buff with a yellowish tinge, marked by varicial streaks of pale brown, 

 which are of irregular width and spacing. The postnuclear whorls are 

 moderately curved with a thin olivaceous-yellow periostracum, which 

 shows hydrophanous, retractively slanting, axial bands that give to 

 the summit of the turns a smooth falsely toothed appearance. The 

 interior of the aperture is bluish white, pearly. The broadly expanded 

 peristome is pale rose-color. Nuclear whorls almost 3, forming a 

 moderately acute apex. The first two are marked by fine incremental 



1186—38 9 



