have settled upon the valves of the older oysters, the variations 

 in size which do exist being referable to unequal nutrition, as 

 is so often seen in the case of a mussel scalp, so here those 

 individuals most crowded are of distinctly smaller size than 

 where they are more freely spaced. 



The equal age of the whole of the oysters over the bed 

 and the absence of younger generations were also noted when 

 examining the Sinna Paraval bed. 



Karim anal Inlet Bed. 



This bed, which lies on the west side of Karimanal inlet, 

 is situated about one-third up the inlet from its mouth and in a 

 south-east direction from Sambasipallikuppam. The oysters here 

 occur in deeper water than in either of the two beds already 

 described, having a fairly even depth of from 1 to \\ foot over 

 them at low tide ; none are exposed at low tide. 



The bottom, oil which they lie scattered irregularly in small 

 bunches, is a black muddy sand. The bed covers a fairly 

 extensive area ; it is nowhere closely packed, and nowhere do 

 we find a central shoal formed of a massed accumulation of the 

 dead shells of former generations. We may conclude that in its 

 origin it is considerably more recent than either the Sinna 

 Paraval or the Yannanturai bed. 



In appearance the oysters here differ greatly from those of 

 the latter deposits. Instead of being markedly elongate, they 

 are squat and shapely in form, the difference of ratio between 

 length and breadth much less accentuated. The range in size 

 and in presumptive age is also very considerable, and there 

 can be no doubt that on this bed we meet with one principal 

 and older generation and at least two younger generations 

 rather poor in individual numbers. The various generations 

 are mingled without regularity, the younger attached in the 

 great majority of cases to the shells of the older. The range 

 in age appears to run from one to three years. 



The dimensions of six oysters of the oldest generation were 

 found to be as follows : — 



An average of 3*21 inches x 454 inches x 1-29 inch, 



