54 HELIX-AMPELITA. 



regular arcuate riblet-like strise, sometimes a little crispate. Spire 

 convex, little prominent, apex obtuse, shining, dull yellowish, des- 

 titute of cuticle. Whorls 5, a little convex, the first slowly, the rest 

 rapidly widening, narrowly separated by a simple suture ; last whorl 

 large, angular at periphery, slightly descending in front, subdilated, 

 convexly sloping above, compressed and shining beneath, obscurely 

 angulated around the wide, pervious umbilicus. Aperture oblique, 

 lunate, obscurely triangular, outer margin at first straightened, then 

 curved, basal margin rather straight, columellar margin oblique, 

 dilated, calloused, not covering the umbilicus ; peristome thickened, 

 convolutely dilated all around. 



Alt. 14, greater diam. 36, lesser 29 mill. (Mabille. in Bull, de la 

 Soc. Philomathique de Paris, 1885-'86, p. 124, 1886.) 



Madagascar, coll. Ancey. 



H. gaudens Mabille. Shell broadly and profoundly pervious- 

 umbilicate, subdepressed-discoidal, a little thick, solid, scarcely 

 ponderous, slightly shining, rufous ; very minutely punctulate at the 

 sutures, then crispate-malleate ; irregularly striate ; spire a little 

 prominent, somewhat convex, apex large, vitreous-shining ; whorls 

 5-5 J, convex, rapidly widening, separated by a deeply impressed 

 suture ; the last whorl is large, convexly sloping above, irregularly 

 angular at the periphery, deeply and rapidly descending in front, 

 dilated and a little advanced ; beneath it is subcompressed, orna- 

 mented with minute radiating stride, roughened by small granules; 

 around the umbilicus there is a yellowish zone. The aperture is sub- 

 horizontal, subquadrate, lunate, the margins approximating, livid 

 inside ; peristome slightly thickened, narrowly reflexed, the outer lip 

 at first rather straight, then arcuate ; basal margin somewhat 

 straightened, moderately convoluted; columellar margin oblique, 

 expanded, not covering the umbilicus. 



Alt. 27, greater diam. 63, lesser 50 mill. (Mabille, 1. c., p. 125.) 



Madagascar, coll. Ancey. 



H. campelica Mabille. Shell broadly and perviously umbilicate, 

 discoidal-compressed, rather thick, solid, shining, yellowish, seen un- 

 der a lens to be exceptionally decussated and punctulate ; spire 

 plane, apex strong ; obscurely striatulate, buff, shining; whorls 53- 

 6, convex-depressed, earlier subregularly and visibly increasing, the 

 rest rapidly, separated by a whitish, impressed suture ; the last whorl 

 large, complanate above, cylindrical at the periphery, rapidly de- 

 scending and broadly dilated in front, subconvex below, obscurely 



