290 LAND AND FRESHWATER 



This is an interesting form showing, as it does, how exceedingly 

 close and indefinite is the line separating the genus Girasia, with 

 its very degraded shell, from Austenia. 



AusTENiA ROTUNDA, n. sp. (Plate CXXX. figs. 4-4/.) 



Localities. Cachar (1) {J. Wood-Mason), Silchar (,2) {F. Ede). 



Shell flattened oval, membranaceous, old shell fairly solid, 

 surface shiny ; sculpture none ; colour pale chestnut, bright straw- 

 colour when young ; spire very depressed ; suture shallow ; 

 whorls 2, apex white, expanding rapidly ; aperture flatly oval ; 

 peristome extremely thin, a mere membrane; columellar margin 

 very thin, curved. 



Largest specimen, size : maj. diam. 24*5, min. 16-5 ; height of 

 shell 7*5 mm. 



Smaller figured and dissected : maj. diam. 16-0, min. 11-0 mm. 



The shell (1) (figs. 4 6, 4 c) differs from A. yigas in being more 

 tumid and apex more coiled, and from A. resjilendens by the apex 

 being broader and not so closely wound and more symmetrically 

 oval. A closely allied species is A. butleri, but a comparison of 

 the figure of this species on Plate XC. fig. 5 of this volume, shows 

 how much more elongate it is and how the spire is coiled in a 

 different way. The species now described is peculiarly roundly 

 oval in shape. 



The animal (figs. 4, 4 a) is pale ochraceous in spirit with no 

 markings on any part, the foot is very short behind ; the right 

 shell-lobe is a broad rounded flap, the left shell-lobe is continuous 

 with it and ovex'laps the peristome all round, ending near the keel 

 of the foot. The peripodial margin is narrow, the groove above it 

 strong, the next above irregular and not so well defined. The 

 right dorsal lobe is small, the left very well developed. 



Of the shell of this specimen (2), which is not mature, I give 

 drawings (tig. 4 d) enlarged and (tig. 4 e) natural size. I also give 

 a figure of the visceral sac when this shell was removed, the last 

 remnant of the visceral coil is well seen. 



There is a colour variety, having black streaks on the peripodial 

 margin and spotted on extremity of foot. 



Grenus Girasia. 

 {Continued from Vol. II. p. 108.) 



A Girasia in every respect similar in form to hooJceri of the Khasi 

 Hills, ranges far eastward, and was sent me by Mr. M. Ogle from 

 the Diyung Valley, Singpho Hills. It is 50 mm. in length as 

 contracted in spirit Pale ochre, finely mottled all over with pale 

 grey, the peripodial margin fringed with same colour. I distin- 

 guish it as var. maculosa. 



Girasia cacharica, Vol. I. p. 240, was also sent me by Mr. Ogle 

 from the first high range be" ween Cachar and Muuipur. 



