CETACEA. 145 



The brain is large, and its liemispheres well developed ; that portion of the cranium which 

 contains the internal ear is separated from the rest of the head, to which it only adheres by 

 ligaments. There are never any external ears, nor hairs upon the body. 



The form of the tail compels them to flex it from above downwards, to produce a progressive 

 motion ; and it greatly assists them in rising in the water. 



To the genera hitherto included, we add others formerly confounded with the Morses, 

 [and which have since, with still greater propriety, been placed subordinately to the great 

 series of Pachydermata]. They form our first family, or that of the 



Cetacea Herbivora, — 

 The teeth of which have flat crowns, which determines their mode of life ; and the latter 

 induces them to leave the water frequently, to seek for pasture on shore. They have two 

 teats on the breast, and hairy moustaches ; two circumstances which, when observed from 

 a distance as they raise the anterior portion of the body above water, may give them some 

 resemblance to human beings, and have probably occasioned those fabulous accounts of 

 Tritons and Sirens which some mariners pretend to have seen. Although, in the cranium, the 

 bony nostrils open towards the summit, the orifices of the skin are pierced at the end of the 

 muzzle. Their stomach is divided into four sacs, of which two are lateral, and thev have a 

 large coecum. 



The Manati (Mana/us, Cuv.) — 



Have an oblong body, terminated by a lengthened oval fin : their grinders, ciglst in number throughout, 

 have square crowns, marked by two transverse ridges ; there are no incisors or canines in the adult, 

 but, when very young, there are two very small pointed teeth in the intermaxillary Ijones, which soon 

 disappear. Vestiges of nails are visible on the edges of their swimming-paws, which they emplov 

 with some address in carrying their yoimg ; hence the comparison of these organs with hands, and 

 the name of Manatus applied to the animals. From their manner of living, they are also called 

 Sea-cows, &c. ; and from their mammae, Mermaids, &c. 



The Manati (Trichechus manatus, Lin.),— Is chiefly found near the mouths of rivers, in the hottest parts of the 

 Atlantic Ocean ; and it does not appear that those of the American rivers differ specifically from those of Africa. 

 Tliey grow to the length of fifteen feet, and their flesh is eaten, [il. F. Cuvier, from examination of the crania, 

 arrived at the conclusion that the African species (M. senegalensis, X&anson) was satisfactorily distinct ; and a 

 third, from the rivers of Florida, has since been distinguished by Dr. Harlan as M. laiirostris.] 



The Dugongs {Halicore, Illig.) — 

 Have grinders composed of two cones laterally united : the teeth implanted iu the incisive bones 

 continue to increase in length, till they become true pointed tusks, but are in great part covered by 

 thick fleshy hps, that are bristled with moustaches. The body is elongated, and the tail terminated by 

 a crescent-shaped flapper. 



We know but of one species (//. dugong), which inhabits the Indian Ocean, and has been confoimded by several 

 travellers with the Manati. Like that animal, it has been named Siren, Sea-cow, &c. [There is reason to suspect 

 the existence of several species of this genus ; that of the Red Sea is described by M. Ruppell hy the appellation 

 H. tabernaculus.'] 



The Stellerines {Rytina, Illig.) — 



Appear to have only a single composite grinder on each side, with a flat crown, and elevated ridges of 

 enamel. Their swimming-paws have not even the little nails observal)le in the Manati. According to 

 Steller, the first, and hitlierto the only one who has described them, their stomach also is much more 

 simple. 



But one species is known, which inhabits the southern jiarts of the Pacific Ocean. [It is entirely roveicd with 

 a thick rugged cuirass, formed of agglutinated hairs, like the hoofs of ungulated quadrupeds. 



The second family, or the animals which constitute the 



Cetacea Ordinaria, — 

 Are distinguished from the preceding by the singular apparatus from which they have 

 received the apjicUation of Blowers. As with their prey they nccessarilv engulf, in their 



