ORDER CETACEA. 451 



The cranium of the Common Dolphin is externally very 

 convex ; its neck is very short, and it results from this 

 conformation, united to the close adherence of the atlas 

 which is the first of the cervical vertebrae, to the second, 

 that no motion of the head can be independent of the body. 

 Like the majority of other Mammalia, it has thirteen dorsal 

 vertebra?, and fifty-three lumbar, sacral, and coccygian. All 

 are surmounted by apophyses less elevated in proportion as 

 they approach the vertebrae of the tail. These last are fur- 

 nished with apophyses, which also diminish gradually as far 

 as the three last caudal vertebras, which are destitute of 

 these processes ; the ribs adhere intimately to the dorsal 

 vertebrae. 



The diameter of the body does not exceed one-fifth of its 

 total length, which is almost nine feet. The animal is con- 

 sequently less embarrassed in its abrupt and rapid move- 

 ments, to which the force of the muscles of the tail and of 

 that of the fin which terminates it, contributes most mate- 

 rially. This fin is divided into two large lobes a little 

 sloped, the width of which is nearly equal to two-ninths of 

 the total length of the animal. 



The skin of this dolphin is smooth, soft, and shining. 

 These qualities are derived from the coat of fat immediately 

 under it. The colour of the epidermis is sometimes of a 

 livid brown, sometimes blackish on the back, and pearly 

 gray on the sides and belly, patched with black. Sometimes 

 it is of a gray more or less deep, and sometimes of a 

 lustrous snow-white. The flesh below the fat is hard, and 

 often exhales a fetid and most unpleasant odour. Gesta- 

 tion continues for ten months, and the female rarely brings 

 forth more than one at a birth. She suckles the young 

 with the utmost care, carrying it under the pectoral fins 

 which answer the purpose of arms : while the little one is 

 yet feeble, she exercises it in swimming, sports with it, 

 defends it with the utmost intrepidity, and never quits it 



