1849.] occurring in Afghanisthan. 659 



pale olive green or olive brown, ornamented with close, narrow irregu- 

 lar transverse dashes. General number of whorls in eroded and de- 

 collated specimens, five ; though nine or ten would appear to be the 

 correct number ; wrinkled transversely by coarse lines of increase ; the 

 upper angle of the aperture is never so acute as in M. pyramis, and 

 the sutures are deeper and whorls more tumid at their junction. 



Mr. Benson thought this a mere variety of the preceding shell, the 

 differences being induced by a residence in stagnant waters ; this how- 

 ever can scarcely be the case, since in the very same waters, M . pyramis, 

 likewise existed, with a full spire and all its other characteristics ; even 

 in the uncoloured variety of that species which has the apex partially 

 eroded, the longitudinal furrows and general sculpture of the shell still 

 exist to point out its distinctness. 



This species is not peculiar to Afghanistan, having been first dis- 

 covered by me in 1836 in a garden tank at Pinjore below Simla. Pin- 

 jore shells of 5 eroded whorls, measure If ins. in length, and are finer 

 than Afghan specimens, which do not exceed If ins., while fully formed 

 individuals of M. pyramis from Dadur and the Gangetic Provinces 

 having 1 2 whorls, measure no more than 1 \ in. This alone would ap- 

 pear to settle the question of distinctness. 



Class 2. Conchifera. Lam. 

 Fam. Cyclad^e. 

 1 9. — Pisidium paludosum y (Hutton.) 



Shell minute ; £ of an inch in breadth ; T ^ in height ; oval ; um- 

 bones rather blunt ; very finely striate transversely ; shining dark olive 

 or dusky green. 



Inside whitish. 



A single specimen only was taken in the swampy ground at Chum- 

 mun, on the Kojuck range in Afghanistan. 

 20.— Corbicula — ? 



I refrain from naming this species, which though much larger, ap- 

 pears identical with one of our Indian shells, because I know that Mr. 

 Benson long since showed specimens to Mr. Gray, and it is therefore 

 more than probable that it has been named already, although unknown 

 to me. It is common in canals at Candahar, and attains a size ex- 

 ceeding any I have seen in the Gangetic Provinces, measuring in my 

 finest specimen 1 T \ of an inch in breadth, and one inch in height ; the 



4 q 2 



