1849.] occurring in Afghanisthan* 657 



15. — Planorbis convexiusculus, (Hutton.) 



Animal black or dusky. 



Shell depressed, } of an inch in diameter ; pale horn colour ; 

 polished ; closely and obliquely striate ; whorls 4 or 5 ; rounded ; 

 future well defined ; periphery subangular, but not influencing the 

 aperture, which is ovato-lunate ; umbilicus wide, discovering all the 

 previous volutions ; the whorls rising gradually and spirally from the 

 horizontal, and rounded below. 



Occurs plentifully at Candahar in tanks ; at Quettah and the Kojuck 

 Pass in marshes, and along the marsh lands of the river Helmund at 

 Girishk. 



I have lately ascertained that it likewise occurs in the Gangetic pro- 

 vinces, having taken it from a tank at the foot of a range of hills 

 bordering the grand trunk road, at Tope Chancey. I likewise procured 

 it some years ago from mountain streams at Pinjore below Simla, with- 

 out then observing the difference, as I find it in my store boxes mixed 

 up with P. compressus. It differs from that species in wanting the 

 delicate carina on the peryphery, and in having a lunate aperture with- 

 out the angle on the middle of the outer lip ; in being more convex, 

 with rounder whorls : and in having its volutions wound round on a 

 more open and less horizontal twist.* 



Fam. MELANIADiE. 



16. — Melania elegans, (Benson.) Gleanings in Science, No. 13 for 



1830, p. 22, species C. 



This very beautiful species was found in the Bolan Pass at Beebee 

 Nanee, where in April the pebbly bottom of the stream was perfectly 

 alive with them ; yet on my return to India two years afterwards in 

 February, not a single shell was visible, all having burrowed deep into 

 the sand in order to escape from the chilling wintry temperature of the 

 mountains. 



The largest specimens procured were 1 T % ins. in length, by y'g- ins. 

 wide ; shell turreted, gradually tapering to an acute apex ; each whorl 

 armed with a row of longitudinally raised ribs, tuberculated at the up- 

 per part ; epidermis thin, variously coloured, being sometimes fuscous 



* Had I not sent specimens of this shell to Mr. Benson, who pronounced it 

 new, I should from his description have considered it P. umbilicalis (Benson) from 

 Sylhet. 



4 Q 



