GENERAL, AXATO.MY OF THE SQUID. 



333 



ermen, in their nets, the l>est way to obtain a supply is 

 by a visit to some tishing station upon the seashore. 



K they are to be preserved in alcohol for dissection, 

 they should be placed in about fifty per cent alcohol for 

 a few hours, before the}' are transferred to strong alcohol, 

 and the latter should be changed once or twice during the 

 fii-st three or four da^^s. 



I. External Form. 



1. In an alcoholic or a fresh specimen notice: {a) the 

 long cylindrical body ; (b) the somewhat movable head, 

 with its large eyes (Fig. 176, rf), and with five pairs of 

 tentacle-like arms (Fig. 176, «', a", a'", a"", h) ; (c) the 

 mouth situated in the centre of the space between the 

 bases of the arms ; (d) the tip of the brown, homy beak, 

 which usually protrudes a little from the mouth ; (e) the 

 pair of large triangular fins, which 

 are joined to the surface of that 

 third of the body which is farthest 

 from the head ; (/) a crenated fold 

 of membrane, the olfactory organ 

 (Fig. 176,y), on each side of the 

 head, behind the eyes. 



Fig. 176. — Side view of the head of 

 Loligo Pealii. (Drawn from nature by 

 W. K. Brooks.) 



a. Dorsal arm. a'\ Ventral arm; the 

 tip of this arm on the left side becomes 

 modified in the male as the heetocotylus). 

 b. Grasping arm. c. External opening of 

 eye. d. Eye. /. Olfactory organ, g. Siphon 

 cartilage, h. Xeck cartilage, i. Lateral 

 chamber of siphon, e. Ventral chamber of 

 siphon. k. »etractor muscle of siphon. 

 I. Retractor muscle of head. 



Fig. 176. 



