THE CEPHALOPODA. 



41 



of the foot proper and the epi podia become modified and change 

 their relations. The margins of the foot are produced into more 

 or less numerous tentacular appendages, often provided with 

 singularly constructed suckers, or acetabula ; and the 'antero- 



Fisr. 17. 



sh 





Fig. 17. Diagrammatic section of a female Cephalopod (Sepia officinalis). a, Buccal mass 

 surrounded by the lips, and showing the horny jaws and tongue ; 6, oesophagus ; c, 

 salivary gland ; d, stomach; e, pyloric caecum ; /, the funnel; g, the intestine ; h, the 

 anus ; ', the ink-bag ; k, the place of the systemic heart ; I, the liver ; n, the hepatic 

 duct of the left side ; o, the ovary ; p, the oviduct ; q, one of the apertures by which 

 the atrial system of water-chambers is placed in communication with the exterior ; 

 r, one of the branchiae ; s, the principal ganglia aggregated round the oesophagus ; TO, 

 the mantle; sh, the internal shell, or cuttle-bone. 1, 2, 3, 4, 5, the produced and 

 modified margins of the foot, constituting the so-called "arms" of the Sepia. 



lateral parts of each side of the foot extend forwards beyond the 

 head, uniting with it and with one another ; so that, at length, 

 the mouth, from having been situated, as usual, above the 

 anterior margin of the foot, comes to be placed in the midst of 



