DIFFERENT WAYS OF SWIMMING 



from them, though trying to avoid them as far as 

 possible, are animals of a very different type. These 

 are the cuttlefish or sepias which, in the natural 

 classification, come among the Cephalopod molluscs, 

 near the poulps or octopuses and squids. I have 

 already referred to their bodies enclosed in a cloak 

 which looks like a bag, and the possession of an un- 



Fig. 12. — The Loggerhead Turtle. The animal may be as long as 

 three feet or more, and weigh over 200 pounds. It feeds upon 

 fish and squids. 



dulating membrane on the sides which enables them 

 to swim and thus gives them a curious resemblance 

 to the flat fish. They have, further, greater speed and 

 an additional means of progression. If we touch 

 them with the end of a stick in this tank in which, 

 hitherto, they have remained suspended without move- 

 ment, we see them shoot suddenly backwards, with a 

 movement of withdrawal, the tentacles trailing in the 

 opposite direction; then they pour forth their ink, a 

 thick black liquid which spreads around them like 



5 1 



