On new Shells from Lower Bengal. 



215 



XXVII. — Diagnoses of new Species of Corbiila and Bitliinella 

 from Lower Bengal. By II. B. PuLSTON, F.Z.S. 



The species described in the present paper form part of a 

 small collection recently sent to me for identification by the 

 authorities of the Indian Museum, Calcutta. All were 

 collected in the brackish pools near Port Canning, at the 

 northern extremity of the district known as the Sandarbans 

 in the Ganges Delta, and are the property of the Indian 

 Museum. 



Corbula abbreviata, sp. n. (Fig. t) 



Shell nearly equivalve, roundly ovate, inflated, thin, 

 greyish white, posteriorly obliquely rounded, anteriorly 

 sharply abbreviated, sculptured with rather coarse concentric 

 lines of growth ; umboes small, situated somewhat anteriorly. 



Alt. 3'5, length ■i"25 mm. 



JJah. Port Canning, Louver Bengal ; in brackish pools. 



Type in Indian Museum, Calcutta. 



Fiij. 1. 



Fi-. 2. 



Fisr. 3. 



Corbula ahbrevinta. Corbula Alcochi. 



Fiir. 4. 



Fijr. o. 



Corbula yracilis. 



Corbula Pfefferi. Bithinella canningensis. 



Corbula Alcockij sp. n. (Fig. 2.) 



Shell irregularly rhomboidal, rather ventricoae, thin, 

 whitish, posteriorly rounded, anteriorly produced, angltd 



