154 Journ. of the Asiat. Soc. of Bengal. [May & June, 1915. 
tic of the area; Sphenopus marsupialis, a free-living flask 
shaped actinian, is also found, together with numerous simple 
ascidians with tough tunic and elongated. siphons; the latter 
of oysters available for fishing. A conservative estimate put 
the number at a total of 20,000,000, after making all allow. 
ances. 
The smaller bed located consisted of patches lying in 4 
fathoms off Karangadu, a Christian village 7 miles south-west 
of Tondi. These oysters were appreciably older than those of 
the Tondi bank, being very little mixed with individuals oi 
younger generations. Very few other living organisms 0 
the larger ones of those living. None of this damage appearé 
to be due to Cliona, but the borings of Polydora hornelli, Wit 
large valuation samples. On my return to Tuticorin, these 
were washed under my personal superintendence and the pearls 
found were then valued by two Indian pearl merchants. The 
larger bed gave a lower pearl value than that of Karangadt, 
namely Rs. 7-9-0 per 1000 as against Rs. 10-7-0 for the latter: 
. J r; of 
sized pearls only 3 were found in the sample of 4300 oyster, 
whereas there were 19 pearls of equivalent size in 5600 oy§ 
d, one 
from the Tondi oysters was of much larger size than a) 
found in the other lot and would have been worth a Jat : 
