CLASS CEPHALOPODA. 



FIG. 71. 



ORDER DIBRANCHIATA (di brang ke a'ta). 



The "two-gilled" Cephalopods have the shell, when 

 present, internal, and either calcareous or horny. When 

 horny, it is long and pen-like, supporting the body. An 

 ink-bag is invariably present, the contents of which the 

 animal, on being frightened, ejects, as a cloud, into the 

 water, to hide its escape. 

 The body is often capa- 

 ble of rapidly changing 

 its color. 



The Argonauts 

 (ar'go nats) are so called 

 from the fabulous ac- 

 count of their using 

 their delicate shell as 

 a boat, some of their 

 tentacles as oars, and 

 others expanded, as 

 sails. Though the male 

 is shelless, the much 

 larger female secretes 

 a delicate unchambered 

 shell, in which she rests and where she deposits her eggs, 

 but to which she is not attached, holding it merely, and 

 swimming rapidly about by forcibly ejecting water through 

 her siphon. 



The Octopus (ok'to ptts), instead of being found in deep 

 seas like the Argonaut, inhabits the rocky shores. This 

 animal, often called the Devil Fish, and about which the 

 most blood-curdling stories have been told, is realty of a 

 timid and retiring disposition. The body is short and 

 oval, while the arms are elongated and provided below 



Ar go nau'ta ar'go. Paper Argonaut. 



