42 HELIX-AMPELITA. 



brown umbilicus. Aperture nearly horizontal, truncate-oblong; 

 peristome narrowly reflexed, the margins converging, joined by a 

 slightly sinuous callus ; basal margin straightened, dilated at the 

 umbilicus. (Pjr.) Alt. 19, greater diam. 40, lesser 33 mill. 



Near the Bay of Diego-Suarez, Madagascar. 



If. lachesis Fer., DESK, in FERUSSAC, Histoire, p. 57, t. 69H, 

 f. 3, 4. PFR. Monographia iii, p. 239, and iv, p. 288, V, p. 375. 



The species belongs near H. duvalli. The figured is copied from 

 Ferussac, and the description from PfeifFer, who drew it from a 

 specimen in the Albers collection. It has not been noticed by other 

 authors. 



H. CLOTHO Ferussac. PL 6, figs. 78, 79, 80. 



Shell orbiculate-subdiscoidal, depressed, with very obtuse apex ; 

 whorls 5J, first depressed, angular at the periphery, the others 

 slightly convex, the last very obtusely angled at periphery; base 

 broadly umbilicated ; aperture oblique, ovate-oblong, margins thick- 

 ened, reflexed, joined on the parietal wall. (Desk.) 



Alt. 26, diani. 48 mill. 



Around the Say of Diego-Suarez, Madagascar. 



H. clotho DESK, in FERUSSAC, Histoire i, p. 57, t. 691, f. 3. PFR.. 

 Monographia iii, p. 238. 



Known only by the original description and figures which were 

 drawn from a dead, bleached specimen. It is evidently closely 

 allied to H. lachesis and If. duvallii, but has a more curved basal lip 

 than either. 



Species not grouped. 



H. PERCYANA E. A. Smith. PI. 10, figs. 26, 27. 



Shell rather thin, globose-depressed, moderately umbilicated, 

 sculptured all over with granules arranged in transverse series, and 

 very oblique lines of increment; olive-brown, sparsely zigzagly 

 streaked with opaque white. Whorls 4, rapidly increasing, convex ; 

 the last large, inflated, descending in front. Spire rather prominent, 

 obtuse at apex. Aperture large, transverse, oblique, nearly subhori- 

 zontal, lilac colored inside ; peristome white, narrowly expanded and 

 reflexed, margins approximating, columellar margin oblique, straight- 

 ened, scarcely arcuate. (Smith.*) 



Alt. 18, greater diam. 31, lesser 22^ mill. 



Ankafana, Betsileo, Madagascar^ 



