1882. J MOLLTJSCAN FAUNA OF MADAGASCAR. 377 



The peristome is very similar ; and the sculpture is somewhat of the 

 same character. Still there are differences of form, of colour, in the 

 sutures, and in the size of the aperture, which readily distinguish 

 these forms, which no doubt inhabit different districts of the island. 



Var. a. 



Shell with a less elevated spire, shorter and broader whorls, more 

 widely umbilicated, with a larger and more oblique mouth, and the 

 outer lip not stained with rose. 



Greatest diam. 30 millim., height 24. 



Hab. Betsileo (Cowan). 



Var. b (Plate XXI. fig. 3). 



Shell a trifle more ventricose than var. a, with the umbilicus 

 similar to that of the type, but the aperture larger and the peristome 

 white, with the body-whorl smoother, with fewer and subobsolete 

 spiral lirae, except within and around the umbilicus. 



Greatest diam. 30 millim., height 264. 



Hab. Betsileo (Cowan). 



Cyclostoma congener, sp. nov. (Plate XXI. fig. 1.) 



Shell openly umbilicated, subdepressedly turbinate, rather smooth, 

 obsoletely spirally sulcate, striated with lines of growth which are 

 puckered and distinct at the sutures ; bright yellow, longitudinally 

 streaked with a darker tint, dark cinereous behind the white expanded 

 lip, encircled at the periphery by a vivid purple-brown band and 

 with two or three hair-like lines of a paler colour, both above 

 and below the middle. Spire elevated, conical, ending in a bluish 

 obtuse tip. Whorls 5|, very convex; the last large, strongly lirate 

 around and within the umbilicus, where it is stained with purple- 

 brown. Aperture large, obhque, ovate-subcircular, light brown 

 within except near the lip, where it becomes of a very dark chestnut- 

 brown or nearly black, this colour extending along the inside of the 

 columellar edge. External band and lines visible within. Peristome 

 roundly expanded and reflexed, white, broad on the dextral margin, 

 narrower on the columellar side. 



Greatest diam. 34 millim., height 30. 



Hab. Tanala province (Coioan). 



This form approaches most closely to C. consanguineum of Sowerby 

 (=. C. obsoletum of Reeve, not of Lamarck), but may be distin- 

 guished by its greater size, its yellow colour, dark apex, and rather 

 more elevated spire. Both species have the same disposition of the 

 spiral bands and lines — namely a single central broad zone, two 

 narrower ones between it and the suture, which are visible on the 

 spire, and two others beneath it and around the lower surface of the 

 whorl. In some specimens of C. consanguineum some of the sulci 

 around the umbilicus are also of a dark colour. On holding up a 

 specimen of C. congener to the light, three lines above and three 

 below the broad band are generally observable. C. obsoletum of 

 Lamarck, according to Delessert's figure (Recueil, pi. 29. f. 1 1«) 



