wm m 



ri. 55. L 147. 



Boring Molluscs and Sponge, x ' . 



Top : Left, Sn.vic'<iva rvgosa ; centre, Oyster bored by Sponge, Clionc. 



liigbt, the Piddoek (Pholas cfaciylTs). 



lk)ttoin : Red Sandstone bored by various kinds of Fiddcek, 



(pp. 147, 148, 149). 



