52 HELIX-AMPELITA. 



sub-straight, armed with a little-conspicuous lamina. Alt. 18, greater 

 diarn. 41, lesser 34 mill. In this species the shell is orbicular- 

 depressed with a moderate, well-rounded umbilicus, not widened, and 

 showing the whorls : the shell is thin, solid and strong, finely striate ; 

 the prominent spire is a regular, elevated cone ; the apex is very ob- 

 tuse, compressed ; the suture is linear, quite superficial on the earlier 

 whorls, becoming a little profound at the last. The last whorl is 

 large, a little compressed -sloping, feebly angular at the periphery, 

 not descending, and a little dilated at its termination, compressed- 

 flattened below, and plainly rounded around the umbilicus. (Ma- 

 bille, 1. c., p. 150.) 



Madagascar. 



H. lychna Mabille. Shell subdepressed-orbicular, broadly and 

 perspectively umbilicate, solid, subopaque, a little shining, rubes- 

 cent, unicolored above, beneath ornamented with a more or less con- 

 spicuous whitish zone, densely striate, under a lens very minutely 

 roughened, here and there malleated ; spire a little convex, prom- 

 inent ; apex minute, obtuse, striatulate, concolored ; whorls 6, con- 

 vex, regularly and rapidly increasing, separated by impressed sutures, 

 the last large, a little convex above, compressed and a little 

 angulated at the periphery, descending at the aperture ; beneath 

 complanate-depressed, rubescent tinged around the umbilicus, and 

 encircled by white, a little convex ; aperture oblique, slightly lunate, 

 obscurely ovate-trigonal ; peristome narrow, reflexed, a little thick- 

 ened, margins approximating, the outer obliquely descending, then 

 arcuate, basal substraight, columellar arcuate, subpatulous. Alt. 21- 

 22, greater diam. 45-48, lesser 39-402 mill. The shell is large, 

 orbicular-depressed, of a brownish-red, quite dark, unicolored above, 

 but ornamented beneath with a white zone around the umbilical 

 tract ; the striae are quite strong, nearly regular, and are accompanied 

 by malleations, visible especially at the periphery ; and under a 

 strong lens little points or strise longitudinally disposed, are visible. 

 The spire is moderately salient, the apex small and obtuse ; the last 

 whorl is well-developed ; it is convex above, a little compressed at 

 the circumference, presenting at this place an inconspicuous angle; 

 compressed beneath ; this compression ceases at the white zone 

 around the umbilicus; the aperture is oval, but visibly tetragonal; 

 the peristome, very little thickened and obtuse, is feebly but narrowly 

 reflexed. (Mabille, 1. c., p. 151.) 



Madagascar. 



