MANATID& 215 



The existing genera present such well-marked distinguishing 

 characters that it is on the whole convenient to place them in 

 separate families, although, as in so many similar cases, our know- 

 ledge of the extinct forms, imperfect as it is, goes far to bridge over 

 the distinction between them. 



Family MANATID^E. 



The characters of this and the two following families may be 

 conveniently included under the heading of the single genus by which 

 they are respectively represented. 



Manatus. 1 Incisors -f , rudimentary, concealed beneath the horny 

 oral plates, and disappearing before maturity. Molars \\, but 

 rarely more than |- present at one time, the anterior teeth falling 

 before the posterior come into use ; similar in characters from 

 beginning to end of the series ; with square, enamelled crowns, the 

 grinding surface raised into tuberculated transverse ridges. The 

 upper teeth with two ridges and three roots, the lower teeth with 

 an additional (posterior) ridge, or talon, and two roots. The cer- 

 vical vertebrae present the remarkable anomaly of being reduced to 

 six in number, the usual vertebral formula being C 6, D 1 7, L 2, 

 and C 23-25. Rostrum of the skull, formed by the union of the 

 premaxillae in front of the anterior narial aperture, shorter than the 

 length of the aperture and scarcely deflected from the basi-cranial 

 axis ; premaxillae and mandibular symphysis not markedly deflected 

 (Fig. 72). Tail entire, rounded, or shovel- shaped. Rudimentary 

 nails on the fore limbs. Caecum bifid. Habitat the shores of, 

 and the great rivers which empty themselves into, the Atlantic 

 within the tropics. These animals are rather fluviatile than marine, 

 ascending large rivers almost to their sources. 



The Manatee may be selected for a somewhat full description, 

 as being one of the best known representatives of this very remark- 

 able order. 



The name Manati was apparently first applied to this animal by 

 the early Spanish colonists of the West Indies, in allusion to the 

 hand-like use which it frequently makes of its fore limbs ; by English 

 writers from the time of Dampier (who gives a good account of its 

 habits) downwards it has been generally spelt " Manatee." It was 

 placed by Linnaeus in his heterogeneous genus Trichechus, but Storr's 

 name Manatus is now generally accepted for it by zoologists. The 

 question of the specific distinction of the African and American 

 Manatees Avill be treated of further on, but it will be chiefly to the 

 latter and better known form that the following description applies. 



The size of the Manatee has been much exaggerated, but 



1 Storr, Prodromus Mcth. Mamm. p. 41 (1780). 



