170 



MADRAS FISHERIES BULLETIN 



VOL. XIV, 



the more recent of the former under which it has been described 

 are Ostrea gryplioidcs van ciittackcusis in the Records of tbe Geolo- 

 gical Survey, and O. madrasoisis by Preston.* It has, however, no 

 outstanding differences from the common American species and I 

 agree with Vredenburg in believing it to be in no wise separable 

 from this widely distributed form. In Tamil ii is known as ali at 

 Madras and Pulicat, patti at Tuticorin ; in Malayalam it is muringa 

 in Travancore and Cochin, muni in Calicut. 



Fig. 4I. A. Ribbed Ark->hell ( Arci ^i:raiiosa). X I. 



B. Common Backwater clam f'JA?'6'/;-zt- ra^Mj. X \- 



C. Backwater Oyster (Ostrea virgittiana). X \- 



It is very hardy and can sustain considerable fluctuations in the 

 salinity of the water it lives in. Hence it thrives in nearly every 

 estuary and backwater on both the coasts of the Presidency ; only 



* Preston, H. B. " Report on a collection of Mollnsca from the Cochin and 

 Enniir backwaters." Records of the Indian Museum^ Vol. XII, pt. i, Calcutta, 1916. 



