178 



MADRAS FISHERIES BULLETIN 



VOL. XIV, 



Bladder-shell it is weak and toothless. The foot is short. The 

 hemispherical valves, papery and delicate, occasionally nearly two 

 inches in diameter, are very common along the shore at Tuticorin. 



The Galcommidae are all tiny creatures, remarkable for the way 

 the mantle folds are reflected outwards over the edgesof the valves, 

 nearly concealing them. The foot is long and flattened on the 

 underside after the gastropod fashion and for the same purpose — 

 crawling. To this family I refer a beautiful little creature I found 

 once at Pamban. As is shown in fig. 44, drawn whilst alive, the 



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Fig 44. A Galeommid {Scintilla hanUyi) from Pamban showing the (latlened crawling 

 foot and the mantle reflected almost entirely over tht valves. X 4. 



inner edge of the mantle is furnished with six long cylindrical 

 tentacles, tapered towards tlie free end. These are coloured brown 

 madder, shading from the tip to the base, where they shade into 

 the pale buff of the mantle. The edge of the mantle has a line of 

 madder running along it while the surface is covered with many 

 minute madder brown tubercles. The upper surface of the fore- 

 part of the foot is also madder-tinted, the base white. 



The Black Clam {Vdorita cochineusis) called in Malayalam Kar 

 erunthu, is our most conspicuous member of the family Cyrenidac. 

 It is a small thick-shelled clam found only in the West Coast estua- 

 rine backwaters, where it is associated with the common clam 

 {Mcrctrix ovum). Its shell is ribbed concentrically and covered 

 by a coarse thick blackish-olive periostracum frequently worn away 

 by corrosion at the umbo, showing the whitish shell beneath. The 

 interior is characteristically pale pink in tint. This clam can 

 survive the prevalence of fresh-water conditions longer than the 

 common clam ; it was originally as other Cyrenids still are, a purely 



