The Marine Molliisca of Bombay. ly 



The Marine Mollusca of Bombay. By James Cosmo 

 Melvill, M.A., F.L.S., and Alexander Abercrombie. 



{Received November i^th, i8g2.) 



(a) General Remarks. 



The shores of the coast in the vicinity of Bombay are of 

 trap rock, with occasional sandy bays. Running behind 

 the coast-hne are immense tracts of low-lying land (at 

 times covered by the sea), or tidal creeks, with slimy mud 

 banks, and mangrove bushes. During the rainy season, 

 the fall in which averages some 80 inches, these creeks and 

 swamps become the mouths of rivers, and for many months 

 the water contained therein must be very brackish. These 

 bring down and pour into the sea a nearly perpetual stream 

 of mud-laden water, and the ocean for some distance around 

 Bombay is, therefore, rarely clear enough to enable one to 

 see down into its depths, even a few feet. 



In consequence of the rocky nature of the coast, and, 

 not least, the mud, dredging does not seem to answer, and 

 the collector must, therefore, be satisfied with what can be 

 found between tide marks, and, happily, the expanse of shore 

 at the lowest spring tides laid bare is considerable, and it 

 is on these occasions that the rare cowries, e.g., C. Lamarckii, 

 lentigiitosa, and ocellata, are collected in fine living condition. 



Both univalves and bivalves, the latter especially, are 

 largely collected by the fisherman class for edible purposes. 



The common oyster, for instance, {O. crenulifera), clus- 

 tered in masses on rocks left bare at half-tide, is broken 

 open by means of a small hammer or stone, aud the animal 

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