COCHLOSTYLA OF MINDORO PROVINCE 



405 



The interior of the aperture is white, showing the dark bands within. 

 The peristome is white. Nuclear whorls 2, well rounded, forming an 

 almost flat apex. The postnuclear whorls are inflated and strongly 

 rounded, marked by retractively curved lines of growth, which extend 

 to the umbilicus on the last whorl, and by fine microscopic spiral 

 striations, which are present on spire and base. The aperture is 

 almost circular, oblique. The peristome is slightly expanded and 

 reflected, somewhat excavated on the columellar side. The parietal 

 wall is covered by a thin callus. 



The type (U.S.N.M. no. 313574) was collected by Pedro de Mesa 

 on Mount Sapol near Calapan, Mindoro. It has 4.9 whorls and 

 measures: Length, 30.8 mm; greater diameter, 31.8 mm; lesser 

 diameter, 27.8 mm. 



Five topotypes (U.S.N.M. no. 313573), from the same source, 

 yield the following measurements: 



The last specimen received a bad injury in the early state of its 

 development, which may be responsible for its dwarfing. 



Two of the specimens before me have only two basal bands plus the 

 dark columellar area. 



This race is distinguished from typical julgens in lacking the dark 

 olivaceous-yellow base. Here the base is only a trifle more yellowish 

 than the spire. 



COCHLOSTYLA (HELICOSTYLA) DIMERA (Jonas) 



Plate 97, Figures 7-9 



1846. Helix dimera Jonas, Abh. Naturw. Ver. Hamburg, vol. 1, p. 123, pi. 11, 



figs. 19, 19a. 

 1846. Helix jonasi var. /3, Pfeiffer, Proc. Zool. Soc. London, 1845, p. 126. 

 1848. Helix dimera Pfeiffer, Monographia heliceorum viventium, vol. 1, p. 226. 

 1850. Helix dimera Pfeiffer, Martini-Chemnitz Conchylien Cabinet, ed. 2, vol. 1, 



Abt. 12, Theil 2, p. 299. 



1850. Helicostyla dimera Albers, Die Heliceen, ed. 1, p. 104. 



1851. Helix dimera Reeve, Conchologia iconica, pi. 16, fig. 61. 



1853. Helix dimera Pfeiffer, Monographia heliceorum viventium, vol. 3, p. 172. 



1855. Helicostyla dimera H. and A. Adams, The genera of recent Mollusca, vol. 2, 



p. 191. 



1856. Helicostyla dimera Pfeiffer, Malakozool. Blatter, vol. 2, p. 145. 



