PIRATES OF THE DEEP— STORIES OF THE SQUID AND 



OCTOPUS. 



By Paul Bartsch, 

 Curator of Marine Invertebrates, U. S. National Museum. 



[With 19 plates.] 

 INTRODUCTION. 



The largest, the most highly organized, as well as intelligent, and 

 therefore, most interesting invertebrate creatures of the sea belong to 

 the class of organisms known as Cephalopods, a group of marine 

 mollusks embracing the Nautilus, Squid, Cuttlefish, Octopus, Argo- 

 naut, as well as the Nautiloids, Ammonites, and Belemnites of the 

 ancient seas. 



The old forms, geologically speaking, as far as known, were all 

 shell-bearing organisms. Their changing from the cramped condi- 

 tion of an inclosing and confining exoskeleton or shell to an endo- 

 skeleton or pen, or even no skeleton, came only in very recent times 

 and carried in its train of development not only possibilities of 

 bodily expansion, as shown by the giant squid of our seas, but pro- 

 duced even greater and far more important consequences, namely, 

 the development of a highly specialized brain, which to-day easily 

 places this group in the first rank of all the invertebrate dwellers of 

 the sea when viewed from the standpoint of mentation. 



Compared with our squids, the chambered Nautilus, the relic of 

 the most ancient stock, is an extremely stupid animal. 



PAST HISTORY. 



In order to follow the customary line of the biogi^apher, we must 

 first give a bit of attention to the ancestors of our subjects and to 

 this alone one might well devote the entire space allotted to our 

 sketch. Paleontology has taught us that these wonderful creatures 



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