74 VERTEBRATES: MAMMALS. 



length. The largest specimen recorded was seventy-six 

 feet in length, and thirty-eight feet in girth. The head 

 constitutes one third of the whole animal. In this spe- 

 cies the atlas is separate, but all the rest of the cervical 

 vertebrae are consolidated into one. The Sperm Whale 

 is usually found in companies of twenty to one hundred 

 or more, and these companies are composed of females 

 and their young and an old male. The Sperm-Whale 

 fishery has employed at one time six hundred American 

 vessels and fifteen thousand American seamen. 



DELPHINIM:, OR DOLPHIN FAMILY. This Family com- 

 prises Cetaceans which are included in the Linnaean ge- 

 nus Dolphinus, and whose head bears the usual propor- 

 tion to the body, and whose jaws are both armed with 

 simple and generally conical teeth, which they shed more 

 or less with age. They live in communities, and are the 

 most rapacious of the whole order. 



The Genus Delphinus Dolphins proper is charac- 

 terized by a convex forehead and a beak-like muzzle. 

 The species are quite numerous, varying from six to 

 fifteen feet in length, and are celebrated for their great 

 velocity of movement. 



The Common Dolphin, D. delphis, Linn., of all seas, is 

 six to ten feet long, with from forty to forty-seven slender, 

 arcuate, and pointed teeth on each side, both above and 



Fig. 61. 



Common Dolphin, D. delphis, Linn. 



below ; the color black above and white beneath. This 

 is the Dolphin of the ancients, so celebrated for its al- 

 leged docility and fondness for music. 



