PHYLUM MOLLUSCA 



307 



nectives, form a ring round the gullet. There are a pair of 

 large eyes situated on the head. In the cuttle-fishes and 

 other Dibranchiata these have a highly complicated structure, 



--J 



Fig. 192. — Sepia officinalis, jaws. A, in 

 situ; B, removed and slightly enlarged. 

 I From the Ca mbridge Natural History .) 



Fig. 193. — Sepia officinalis, enteric 

 canal, a, anus; b. d, one of the 

 bile ducts; b. m, buccal mass; c, 

 caecum; i, ink-sac; ?'. d, ink-duct; 

 j, jaws; /, /, liver lobes; <:r,cesoph- 

 agus; /, pancreatic appendages': 

 r, rectum; J. g, salivary glands; 

 st, stomach. (From the Cambridge 

 Natural History.') 



and contain representatives of all the principal parts of the 

 eye of a fish or other vertebrate. In Nautilus the eye is of 



1 This organ is by Sedgwick regarded as renal in its nature, being the 

 unpaired portion of the kidneys. (See Sedgwick's Text-book of Zoology, 

 U PP. 433* 437-) 



