384: 



MOLLUSC A. 



Class V. Cephalopoda. 



The Cephalopoda are distinguished among the molluscs by their 

 size and their high organization. The majority measure, includ- 

 ing the arms* from eight inches to three feet in length, a few are 

 smaller (two to seven inches), while especially rare are the huge 

 giants, some of which may be over forty feet in length. These 

 large species for a long time were only known from the tales of 

 sailors, who said that the animals had grasped vessels with their 

 large muscular arms and had drawn them into the sea. In the last 

 half-century some of these forms, belonging to the genus Arclii- 



FIG. 381. FIG. 382. 



TIG. 381. Octopus tonganus from the side. (After Hoyle.) Funnel and mantle fold to 



the right ; back and eyes on the left. 

 FIG. 382. Loligo kobiensis, ventral view. (After Hoyle.) 



teuthis, have been stranded by storms on the coasts of Newfound- 

 land and Japan. One of these Newfoundland specimens had a 

 body twenty feet long from head to tail, and one of the arms was 

 thirty-five feet in length. Since these arms are composed entirely 

 of muscle, it is easily conceivable that they might swamp a small 

 vessel. 



The body of a cephalopod is divided by a constriction into 

 head and trunk. At the extremity of the head is the mouth, and 

 around this a circle of arms or tentacles. Each tentacle is taper- 

 ing and bears on its oral surface rows of suckers (in some species 

 altered to hooks). The Octopoda have eight of these arms, all 



