90 



Shell Life 



geners, in water from 12 to 40 fathoms. Here 

 it builds its nest under large stones, mingling 

 witli the byssus - threads bits of nullipore and 



File-shell in its nest (nat. size) 



fragments of shell, lined within with excrement. 

 The young ones often associate, several in one nest, 

 but the adults are quite solitary. They frequently, 

 however, accommodate guests, who in all probability 



