bivalves: pholads and ship-worms. 



215 



Fig. 443. — Fig. 444. — 



Sphserium. Thyasira. 



Northern Coast of 



States. N. England. 



Fig. 442. — Astarte. Fig. 44.5.— Sphseriun?. 



Coast of New England. Northern States. 



Fig. 446. — Cytherea. Reduced. 

 West Indies. 



Fig. 447. — Maccra. Britain. 



Fig. 449. — Tel- Fig. 450. — Tellina. 

 lina. Our coast. Our coast. 



Fig. 448. — Tellina. Britain. 



Fig. 451. — Eazor-SheU, or Solen. Much reduced. Both shores of the 

 Atlantic. 



PHOLADS AND SHIP-WORMS. 

 Pholads have the shell very hard and rough, like a 

 rasp, and they burrow in all sorts of substances, even 

 in stone. Ship-Worms are long moUusks, looking like 



