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THE POPULAR SCIENCE MONTHLY. 



ing "feet proceeding from the head." Of these the octopus, as its 

 name indicates, has eight feet, or arms ; for, though these long append- 

 ages are sometimes used as feet, they are habitually used as arms. 



Of the octopoda family is the small paper nautilus or argonaut. 

 How few of our readers who have admired this beautiful shell, with its 

 mother-of-pearl lining, have realized that its former inhabitant was own 

 cousin to the horrible devil-fish ! — a female cousin, we must add, for the 

 shell is not connected with the animal organically, but is held in posi- 

 tion by two of the long arms, with the sole purpose of protecting the 

 eggs. The male argonaut has no shell. 



Though all the octopods, large or small, can swim freely at will, 

 such is not their habit ; they prefer to lie concealed, or partially so, on 



Fig. 3.— Paper Nautilus (Argonauta argo). 



the side or in the clefts of rocks. There the octopod's body is protected 

 from the attacks of other animals, whUe it can extend its long feelers in 

 search of prey, of which fish, mollusks, and crustaceans, are the principal 

 objects. Its movements, when an object of food is perceived, are marvel- 

 ously rapid, swifter than the flight of an arrow from the bow of an expe- 

 rienced hunter. The long, flexible arms grasp the victim ; its hundreds 

 of suckers, acting like pneumatic holders, make escape impossible ; and, 

 as the long arms draw the object nearer and nearer, the other shorter 

 arms add their multiplied disks, forming " a perfect mitrailleuse of in- 

 verted air-guns, which take horrid hold, and the pressure of air is so 

 great that nothing but closing the throttle-valve can produce relaxa- 

 tion." This throttle-valve is the neck, as we have before described. 

 Those lengthy appendages, the limbs, are rather in the way when the 

 animal is swimming, and would act as drag-anchors if left pendent ; 

 but the octopus usualh' draws them close alongside, whence they extend 

 in an horizontal position, acting the part of a tail to a kite. It propels 

 itself by drawing in and expelling water through its locomotory tube. 



