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, 



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

 situ; B, removed and slightly enlarged. 

 (From the Cambridge 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; t. d, ink-duct; 

 j, jaws; /, /, liver lobes; cb, oesoph- 

 agus; p, pancreatic appendages 1 ; 

 ■r, rectum; s.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, 

 i* PP-433. 437) 



