CLAMS, OYSTERS, AND MUSSELS 



119 



used as a means of defense. When pursued by an enemy, 

 the squid ejects some of this pigment which colors the 

 water and bhnds the 

 pursuer. 



The body of the 

 giant squid sometimes 

 becomes eiglit or nine 

 feet long, while the 

 largest pair of arms 

 may attain a length 

 of twenty or thirty 

 feet. 



Cuttlefish.— The in- 

 ternal shell of this 

 animal is calcareous 

 and furnishes the 

 cuttle bone so uni- 

 versally used for feed- 

 ing canaries. The 

 body of a cuttlefish 

 is much shorter and 

 more oval than the 

 squid's. Otherwise 

 these two mollusks 

 are much alike. It 

 is from the cuttlefish, 

 Sepia, that the pigment is obtained from which sepia ink 

 is made. See Figure 66. 



Octopus. — The l^ody of the octopus is more or less egg- 

 shaped, and usually not large. A species on the Pacific 

 coast is sometimes found with a body one foot long, six 

 inches in diameter, and with arms twelve to fourteen feet 



Fig. 65. —Squid. 



