20 HELIX-AMPELITA. 



little sunken, light brown or yellowish ; sutures moderately impressed. 

 Whorls 4, convex, rapidly widening, the last very wide, with a 

 slight depression on the upper surface, extending upward on the 

 penultimate whorl, but becoming obsolete toward the aperture ; 

 periphery rounded, but the shoulder has an obtuse angle bounding 

 the spiral depression; the base has also a spiral depression or con- 

 cavity, the surface somewhat malleated within it ; there is a project- 

 ing, very prominent but obtuse angle around the umbilicus ; the 

 whorl descends gradually, but rather deeply in front, and the base 

 has a slight constriction behind the baso-columellar lip. The aper- 

 ture is very large, very oblique, of a livid grayish color inside and 

 a changeable luster ; the peristome is very broadly expanded and 

 rolled backward above, much more narrowly so below, the ends con- 

 verging and connected by a bluish callus. The umbilicus is very 

 much contracted as it penetrates, but opens rather widely. 



Alt. 23 greater diam. 57, lesser 42 mill. ; aperture 34 mill, wide, 

 measured outside of peristome. 



This is a larger species than H. sepulchralis, with the hydrophanous 

 creamy markings much more prominent, the last whorl and aperture 

 decidedly larger, the ridge around the umbilicus very much more 

 prominent. The umbilicus is very much contracted within, and the 

 surface is much more obviously granulated, especially within the 

 umbilicus. Although larger, this shell has a half whorl less than 

 sepulchralis. The spirally impressed base and top give a decidedly 

 sunken and cadaverous appearance to the shell. 



H. ATROPOS Fe>ussac. PI. 5, fig. 77 ; >pl. 63, fig. 44. 



Shell umbilicate, depressed, transversely dilated or oblong in cir- 

 cumference, rather solid, irregularly striate, chestnut colored with 

 three white bands, one near the suture, two wider basal ones ; spire 

 slightly convex, obtuse ; whorls 5, moderately increasing, the last 

 compressed-rounded, deflexed in front, subcompressed around the 

 chestnut colored umbilicus, somewhat constricted in front. Aper- 

 ture very oblique,' ovate-oblong ; peristome narrowly reflexed all 

 around, its terminations approaching, joined by a thin callus. (Pfr.) 



Alt. 18, greater diameter 39, lesser 32 mill. 



Around bay of Diego Suarez, Madagascar. 



H. atropos Fer., DESH. in FERUSSAC, Histoire, t. 69 H, f. 13, 14, 

 p. 56. PFR. Monographia iii, p. 239 ; iv, p. 288. REEVE, Conch. 

 Icon., f. 1347. 



