CLASS OF THE CEPHALOPODA. 



4,69 



suckers, by means of which they attach themselves with 

 much force to the bodies they lay hold of (Fig. 162). In the 



Fig. 451. Nervous System of the Seiche (Sepia). 



* a, the nervous collar surrounding the gullet, the course of which is indi- 

 cated by a bristle (s) ; c, the nervous mass situated before the gullet, and 

 generally called brain : its superior surface is surmounted with a very large 

 cordiform tubercule, and there proceed from its anterior part, nerves, which 

 soon terminate in a circular ganglion, which in its turn gives origin to 

 another pair of nerves which descend under the mouth so as to embrace 



