SPECIES OF MAMMALIA. 



internal ear separate from the head, or adhering by liga- 

 ments; two rudimentary bones lost in the flesh, represent 

 the pelvis and posterior extremities. 



Animals altogether aquatic, comprising the largest species 

 in the world, carnassial for the most part ; swim by the 

 assistance of the tail, which moves up and down, and not 

 from right to left like that of the Fish ; viviparous ; mam- 

 miferous. 



Inhabit almost all seas ; the very large species the more 

 northern; the herbivorous nearer the equator. 



Family I. — Sirenia (Herbivorous Cetacea.) 



Molars with flat coronal; sometimes tusks in the upper 

 jaw; teats two, pectoral; mustachios ; nostrils, properly 

 so called, at the end of the muzzle; nasal apertures in the 

 osseous head situated above ; body very massive. 



Genus I. — Lamantin. Manatus. 



Rondelet, Lin., Scopoli, Storr, Lacep., Cuv., Geoff., 

 Illig. Trichecus, Linn., Erxlsb., Schreb., Shaw, Gmel. 

 Manati, Bodd. 



Incisors %\ canines -S. 2 ; molars ■^;^=38. Incisors very 

 small, exist only in the foetus; adults have but thirty-two 

 teeth, four molars being lost when young; two transverse 

 hillocks on the coronal of the molars; head not distinct 

 from the body ; eyes very small, placed above, between the 

 auditory foramina and the end of the muzzle; auditory 

 foramina hardly visible ; tongue oval ; hinder part of the 

 body very thick, depressed, and rounded at the end ; no 

 caudal fin properly speaking ; some vestige of claws on the 

 edges of the pectoral ; mustachios, composed of a bundle 

 of enormous hairs directed downwards, and forming a 

 kind of corneous tusk on each side ; naked skin, thick and 

 rugous; six cervical vertebrae; six pair of ribs, thick and 



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