56 HELIX-PCECILOSTYLUS. 



scarcely prominent, apex moderate, rugose rib-striate ; whorls 4i- 

 5, convexly plane, depressed at the sutures, rapidly widening ; sut- 

 ure profound, margined by an obtuse carina ; last whorl large, a 

 little swollen above at first, and then sloping, cylindrical at the 

 periphery, beneath a little compressed, marked by a wide white zone 

 around the umbilicus, descending and broadly dilated in front ; 

 aperture oblique, ovate, margins subapproximating, peristome whit- 

 ish, dilated and reflexed ; columellar margin obliquely reflexed, 

 outer incurved, broadly dilato-reflexed. 



Alt. 15, greater diam. 59 i, lesser 50 mill. (Mabille, 1. c., p. 127.) 



Madagascar, coll. Ancey. 



Section PCECILOSTYLUS Pilsbry, 1890. 



Eurystyla ANCEY, in The Conchologists' Exchange ii, p. 39, Sept., 

 1887, type, H. cerina Morel, (not Eurystylus Stal, 1871). Cochlo- 

 styla, in part, of Authors. 



These beautiful shells are like some forms of Ampelita in facies, 

 but are very compactly convoluted, the umbilicus being a mere 

 perforation closed in the adult. The surface is glossy and vividly 

 painted. The anatomy is unknown. There are but two species known 

 at present H. viridis Desh., not an uncommon form in collections, 

 but usually classed as a Cochlostyla ; the other, H. cerina Morel., is 

 still rare. I have seen but a single specimen of it. 



H. VIRIDIS Deshayes. PL 63, figs. 50, 51, 52. 



Shell imperforate elevated-globose, solid, strong, opaque, bright 

 or dark green, with three broad encircling dark brown zones, one at 

 periphery, one above, and one on the base ; the suture is narrowly 

 edged with brown ; on the spire the green ground-color is replaced 

 by yellow and then white, and the zones become light chestnut 

 brown. Surface smooth, polished, scarcely striate ; spire elevated, 

 blunt ; apex very obtuse, corneous ; whorls 5, convex, the last de- 

 scending in front. Aperture very oblique, rather small, obscurely 

 quadrangular, opaque white within, not showing the bands ; peris- 

 tome dark purplish-brown, obtuse, very narrowly expanded all 

 around, dilated and appressed over the umbilical tract, and whitish 

 there; parietal callus thin, transparent. 



Alt. 29, greater diam. 28 mill. ; aperture, oblique alt. 20, breadth 

 17-1 mill. 



