GENERAL ANATOMY OF THE SQUID. 355 



5. On the ventral edge of this is a space (Fig. 186, c), 

 the mouth. 



6. Dorsal to the mouth is the section of the small dorsal 

 jaw (d) of the beak, which is shown in longitudinal section 

 at (d), in Fig. 185. 



FIG. 186. 



Fro. 186. Transverse section through the anterior end of the head of 

 a young specimen of Loligo Pealii ; magnified about twenty diameters. 

 (Drawn from nature by W. K. Brooks.) The shading in fine lines shows 

 the course of the muscular fibres. 



a, a. a. a, a. Transverse section of the arms. 6, b, b, b, b. The bra- 

 chial ganglia and commissures. c. Pharynx, d. Dorsal mandible. 

 e. Ventral mandible. /. Muscles of dorsal mandible, g. Muscles of 

 ventral mandible, h. Lip. i. Tongue. 



7. Between the lateral portions of this jaw the muscle (f) 

 which moves it. 



8. The sides of the buccal mass are formed by the two 

 large muscles (</) which move the ventral or larger man- 

 dible. 



