CHAPTER XIII 



CLASS CEPHALOPODA 



The Cephalopoda present a complete contrast to the majority 

 of the Mollusca in habits and in many points of organisation. 

 In their power of rapid movement and their means of progres- 

 sion, their extreme ferocity and carnivorous habits, their loss, in 

 so many cases, of a shell, and in its constitution when present, in 

 the general symmetry of their parts, in their reproductive and 

 nervous system, they stand in a position of extreme isolation 

 with nothing to connect them with the rest of the phylum. 



Professor A. E. Verrill has collected many interesting details 

 with regard to gigantic Cephalopoda occurring on the north- 

 eastern coasts of America. From these it appears that the ten- 

 tacular arms of some species of Architeuthis measure as much 

 as 32, 33, 35, and 42 feet in length, while the total length, 

 including the body, sometimes exceeds 50 feet. Even off the 

 Irish coast a specimen was once captured whose tentacular arms 

 were 30 feet long, the mandibles 4 inches across, and the eyes 

 about 15 inches in diameter.^ The strength of these giant 

 Cephalopods, aided as they are by formidable rows of suckers 

 and other means of securing a grip, is almost incredible. Cases 

 are not uncommon, in which persons diving or bathing have been 

 attacked, and have with difficulty made their escape. 



Great damage is frequently inflicted by Cephalopoda upon 

 shoals of fish on British coasts. Off Lybster (Caithness) Loligo 

 and Ommastrephes devour the herring, large numbers of which are 

 cut up and bitten on the back of the neck by these creatures. 

 On the American coasts the mackerel fisheries are sometimes 

 entirely spoiled by the immense schools of squid which infest the 



1 Trans. Connect. Acad. v. p. 177; Zoologist^ 1876, p. 4602. 

 378 



