BELEMNITES. 



361 



an internal coiled sLell. The shells of Spirula Peronii La- 

 marck are rarely thrown ashore on Nantucket ; it lives upon 



Pig. 217.— Pearly Kaatllas, JV. pompilius. Seen in section showing 

 the cnamBers and siphancle. Half natural size.— From Tenney'e Zo- 

 ology. 



the high seas. The extinct Belemnites had, like the recent 

 Moroteuthii Verrill, a straight conical shell, the " thunder- 



Pig. — Pouipe or Common Octopus of Brazilian Coast 



bolt " fossil. Allied to Loligo and OmmastrepJies, are gigan- 

 tic cuttle-fishes which live in mid-ocean, but whose remains 



