TORTAXIS. 5 



Length 35, diam. 10, aperture 10x5 mm. 



Length 36, diam. 10.5, aperture 10x5 mm. 



Length 34, diam. 9, aperture 9x5 mm. 



Darjeeling, in forest at the waterfall (Stoliezka). 



Glessula erosa BLANF., Journ. Asiat. Soc. Bengal, xl, 1871, 

 p. 43, pi. 2, f . 7, la. Ackatina e., HANLEY & THEOB., Conch. 

 Ind., pi. 78, f. 5. PFR., Monogr., viii, p. 283. 



''This species is easily distinguished from its local associate 

 G. tenuispira Bens, by its thickness and opacity, and by the 

 character of the surface, which has none of the vitreous lustre 

 so characteristic of most species of the genus. The upper 

 whorls are generally much eroded; the lower, which retain 

 the epidermis, are of a dark straw-color with darker oblique 

 bands at intervals, apparently marking stages of growth. 

 Under a lens very fine dark spiral lines are also perceptible " 

 (Blanford). 



Genus TORTAXIS Pilsbry, n. gen. 



Spiraxis, Euspiraxis and Stenogyra, in part, of authors. 



Shell Stenogyroid, rather large, imperforate or narrowly 

 rimate, turrited or cylindric-turrited with large, obtuse (but 

 not bulbous or cylindric) apex, the first two whorls smooth, 

 the rest glossy, rather weakly striate, convex. Aperture 

 ovate, the outer lip simple or with expanded edge, columella 

 concave above, having a spiral callous fold below, obliquely 

 or vertically truncate at the base. Type T. erectus (Bens.). 



Distribution, southern China, Tonkin and Laos. 



Most of the species are figured on plate 2. 



This group differs from Prosopeas chiefly by the shape of 

 the columella. The shell is also smoother and less attenuate 

 above, and the growth-striae bend forward less. It is not 

 closely related to the true American Spiraxis. 



These snails are apparently viviparous. A young shell out 

 of T. lubriciis is globose, of 2y% whorls, umbilicate, with a 

 short, concave columella which is obliquely truncated, Acha- 

 tina-like at the base. Diam. and alt. 2 mm. (pi. 12, fig. 1). 



Stenogyra pachygyra Gredler, which has much the contour 



