COCHLOSTYLA-HELICOSTYLA. 187 



C. RUSTICA Mousson. PI. 58, figs. 91, 92. 



Ira perforate, oblong, solid, striate, chestnut-colored, covered with 

 a gray cuticle. 



Spire elongate-conic, summit obtuse, nude. Whorls 6, slightly 

 convex, pallidly unifasciate, the last two-fifths of the total length, 

 subinflated, ornamented with a black and a buif band around the 

 umbilical region. Aperture oblique, lunate-circular, milk-white 

 within; peristome narrowly expanded, subthickened ; columella 

 immersed, white, subcallous, quasi-uni dentate. (Mouss.) 



Alt. 53, greater diara. 37, lesser 32 mill. 



Eastern Java. 



Bui. rusticus Mouss., Moll. Java, p. 114, t. 22, f. 1 (1849). 

 REEVE, Conch. Icon. V, t. 78, f. 574. cf. HIDALGO, Journ.de Con- 

 chyl. 1887, p. 149. 



This form is retained separate from C. metaformis only because of 

 its different habitat. Certain forms of metaformis correspond closely 

 with the figures and description of rustica, such as the shell figured 

 as rustica by Hidalgo (pi. 58, fig. 89). Of this last form specimens 

 are before me from Mt. Calanan. Another shell, even closer to 

 rustica, is figured on pi. 58, fig. 90. Figure 92 is copied from 

 Mousson's original illustration. 



C. HYDROPHANA Sowerby. PI. 36, figs. 35, 36, 37. 



Imperforate, oblong-ovate, elevated, thin. Smooth ; straw-yellow, 

 with dark chestnut bands at suture, periphery and columella, and 

 often a narrow band between the last two. Rarely all bands are 

 lacking. Hydrophanous cuticle forming a thin film of oblique 

 shreds, scarcely visible except on the bands. 



Spire elevated, summit obtuse. Whorls 5, the last slightly de- 

 flexed in front. Aperture oval, white and showing the band inside ; 

 lip narrowly expanded and reflexed, white ; columella sub vertical, 

 very deeply inserted, having an obtuse lobe below but not toothed. 



Alt. 33, diam. 25 mill. 



Alt. 25, diam. 22* mill. 



Mindoro, Philippines. 



H. hydrophana Sow., P. Z. S. 1840, p. 88. PFR. in Conchyl. 

 Cab. t. 49, f. 8, 9 ; Monogr. i, p. 222. REEVE, Conch. Icon. f. 69. 

 C. hydrophana HIDALGO, Journ. de Conchyl. 1887, p. 148. 



Very closely allied to C. metaformis, but smaller, thinner, with a 

 less thickened, non-dentate columella. 



