3 Si 



MOLL USCA. 



Class V. Cephalopoda. 



The Cei^lialopoda are distingui.slied among the molluscs by tlieir 

 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 tlie huge 

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

 large species for a long time were onl}' 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- 



FlG. 381. 1 1 ,s 



Fig. .381.— OctopTW foncajnf.s' frnm the side. (After H<»yk ^ tunnel ind mantle fold to 



the riglit: back and e\'es on tile left. 

 Fig. :383. — Loligo kubknt^is, ventral view. (After Hoylc.) 



feufJiis, have been stranded by storms on the coasts of Xewfound- 

 land and Japan. One of tliese Newfoundland specimens had a 

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

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

 of muscle, it is easily conceivalile 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 tentatdes. Each tentacle is taper- 

 ing and bears on its oi-al surface rows of suckers (in some species 

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



