ACHATINIM [Continued] 



Genus BACILLUM Theobald. 



Bacillum THEOBALD in Hanley and Theobald, Conchologia 

 Indica, p. 17, for Achatina obtusa Blanf. and A. cassiaca 

 Bens. Achatina, Glessula and Stenogyra of various authors. 



Shell rather large, solid, imperforate turrited, many- 

 whorled, a little contracted near the obtuse, rounded summit, 

 the embryonic shell cylindric; sculpture of vertical rib-striae 

 beginning somewhere upon the first whorl (pi. 1, fig. 12) ; 

 the post-embryonic whorls being obliquely, regularly rib- 

 striate. Aperture oblique, Achatinoid, the columella con- 

 cave, truncate at the base, outer lip simple. Internal axis 

 slender, strongly sigmoid within each whorl. Soft anatomy 

 unknown. Type B. cassiacum. 



Distribution, eastern India. Figured on plate 1. 



This group would hardly be thought distinct from Homorus 

 were it not well separated geographically from that African 

 genus, at least in the recent fauna. Almost the sole distin- 

 guishing feature is the stronger sculpture of Bacillum. Both 

 groups are merely large and solid forms of the Subulina type, 

 so far as the shells are concerned. 



1. B. OBTUSUM (Blanford). PL 1, fig. 1. 



Shell elongate-turrited, whitish corneous, waxy, rather 

 solid, closely flexuously plicate-striate, plicate under the 

 suture. Spire lengthened, subcylindric towards the apex, 

 which is very obtuse and papillar. Suture slightly impressed, 

 somewhat crenulated. Whorls 12 to 14, nearly flat, the last 

 subangulate at the periphery. Aperture oblique, subovate; 

 peristome simple, unexpanded. Length 48 to 52, diam. 10 to 



(1) 



