GENERAL ANATOMY OF THE SQUID. 



355 



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

 the mouth. 



<j. 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. 

 Fig. 186. — Transverse section through the anterior end of the head of 

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

 (Drawn from natm-e 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. b, 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 (/) 

 "which moves it. 



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

 large muscles [g) \\ hich move the ventral or larger man- 

 dible. 



