116 MAMMALIA. 



ORDER IX. 

 CETACEA. 



The Cetacea are mammiferous animals without hind feet; their 

 trunk is continued by a thick tail, terminating in an horizontal, car- 

 tilaginous fin, and their head is united to the trunk by a neck, so 

 thick and short, that no diminution of its diameter can be perceived, 

 and composed of very slender cervical vertebrae, which are partly 

 anchylosed or soldered together. The first bones of the anterior 

 extremities are shortened, and the succeeding ones flattened and en- 

 veloped in a tendinous membrane, which reduces them to true fins. 

 Their external form is altogether that of Fishes, the tail fin excepted, 

 which in the latter is vertical. They always therefore remain in the 

 water; but as they respire by lungs, they are compelled to return 

 frequently to its surface to take in fresh supplies of air. Independ- 

 ently of this, their warm blood, their ears, with external, though 

 small, openings, their viviparous production, the mammae with which 

 they suckle their young, and all the details of their anatomy suffi- 

 ciently distinguish them from Fishes. 



To the genera of the Cetacea hitherto admitted, we add others 

 formerly confounded with the Morses. 



FAMILY I. 



CETACEA HERBIVORA. 



The teeth of Herbivorous Cetacea have flat crowns; this determines 

 their mode of life, and the latter induces them to leave the water fre- 

 quently, to seek for pasture on shore. They have two raammaB on 

 the breast, and hairy mustachios; two circumstances which, when 

 observed from a distance as they raise the anterior part of the body 

 vertically from the water, may give them some resemblance to hu- 

 man beings, and have probably occasioned those fabulous accounts 

 of Tritons, and Sirens which some travellers pretend to have seen. 



Manatcs, Cuv. 

 The Lamantins, or rather the Manati, have an oblong body, terminated by 

 an elongated oval fin; the grinders, eight in number throughout, have a 



