CLASS CEPHALOPODA. 7 I 



CHAPTER XVIII. 



CLASS CEPHALOPODA. 



The next group of animals is a large one, comprising the 

 various kinds of Cuttle-fishes and the Pearly Nautilus, 

 all of which live in the sea. The name of the group is 

 CepludoTjoda (from the Greek, l:e2:)hcde, head, and podes, 

 feet), so called because the head is surrounded by a 

 series of " arms," or muscular processes which the animal 

 uses for walking with at the bottom of the sea. As the 

 representative of these animals we shall select the conimou 

 Calamary {Loligo vidgaris) of British seas. This singular 

 creature (fig. 31, A) grows to a length of from a foot and 

 a half to two feet, and is not uncommonly found stranded 

 on the shore after heavy storms. The animal consists, as 

 can readily be seen, of two portions — an anterior or front 

 portion, carrying the eyes, and a posterior or hinder por- 

 tion, into which the former is loosely fitted in front. The 

 hinder portion is the body proper, and is of a cylindrical 

 or rounded shape, furnished behind with a broad trian- 

 gular fin on each side. These fins give the hinder end of 

 the body a somewhat lozenge-shaped form, and they enable 

 the animal to swim with great power and rapidity. The 

 whole of the body is enclosed in thick leathery skin, of a 

 bluish colour, and covered with numerous purplish-red 

 specks and blotches. The under surface is of a lighter 

 tint, and the animal can change its colour at will, and can 

 thus adapt itself to the colour of surrounding objects. 



The anterior portion of the body carries on its sides a 

 pair of large, conspicuous, globular eyes, and bears in 

 front a circle of muscular processes or "arms." These 

 arms are ten in number, eight of them of equal size, and 

 the remaining two veiy much longer than the others. 

 The eight short arms (fig. 31, A, a) are furnished on 

 their inner surfaces with two rows of little cups, or 



