74 MOLL USC A. 



upon the bottom among the rocks. The body (Fig. 78) 

 is a simple sac, from which radiate eight sucker-lined 

 arms. They are very powerful, and when enraged waves 

 of color pass over the skin in rapid succession. When 

 attacked they eject a cloud of ink, and under its cover 

 crawl away, passing through incredibly small holes, and 

 so mimicking the colors of the bottom that an experi- 

 enced eye is necessary to detect them. They feed upon 

 crabs and other animals, and are mainly bottom animals, 

 though some species have web-like membranes between 

 their eight arms enabling them to swim. Each egg of the 

 octopus is inclosed in a thin, transparent, oval case, and 

 attached by a stalk with several hundred others to the 

 bottom ; sixty species are known. 



VALUE. The fisheries are important to the Chinese. 



Argonaut (Argonautidc^.Tte Cephalopods of this 

 family are often incorrectly figured with sails raised in the 

 air. The shell is symmetrical and of great delicacy and 

 beauty. The animal rests in it, the upper or dorsal pair 

 of arms being developed at their tips into membranes that 

 are thrown back over the shell (Fig. 79), holding the 



FIG. 79. Argonauta argo. A, female with the expanded arms in their nat- 

 ural position, embracing the shell, b ; d, the other six arms ; a, the 

 funnel. B, suckers. 



Argonaut in. The broad tentacles also contain the shell- 

 secreting glands. The shell is likewise the nursery, the 

 eggs being attached within it and carried about. The 

 male secretes no shell, and is extremely small. They are 

 deep-water animals, and crawl about upon the bottom 



