MANATUS. 155 



Family 11. MANATID^. 



(Kepresented by a single genus.) 



I. MANATUS. (Man.) 



(Manatee, Lamantin.) 



Manatus, Starr, Prodromus, Meth. Mamm., 1780. 



Skull with rostrum almost in the line of the axis of 

 the base of the cranium ; premaxillse and symphysis 

 short, only slightly bent downwards ; rough sur- 

 face supports horny plate. Rudimentary nails on 

 pectoral limbs ; six cervical vertebrae, the formula 

 C(;Dj7L2jCd23_25 = 67 or 69. Colour greyish. Tail 

 horizontal, not flanged but shovel-shaped. Pectoral 

 limbs flattened ovoids like paddles ; no dorsal fln ; 

 nostrils at end of muzzle ; upper lip mesially divided 

 into two lobes. Length about 8 feet. Three species are 

 recognised : Manatus senegalensis from West Africa ; 

 M. americanus or australis from South America, 

 West Indies, Surinam ; J\I. inunguis from the 

 Amazon and Orinoco rivers. 



(1) Manatus senegalensis. (Man. s.) 



Adamson, Hist. nat. du Senegal, p. 143. 



Zygomatic process deep, jugal deep, upper margin of 

 anterior nares smooth and rounded, beak and sym- 

 physis of mandible short and shallow. 



1. Skull, occipital bone lost; bony ring of orbital aperture 

 not quite complete behind, long diameter 2| inches, 

 vertical If inch; anterior nares large, lozenge-shaped, 

 sagittal diameter 5^^ inches, transverse 3f inches, 

 upper half of lateral border of, smooth, rounded ; septal 

 cartilage extends from frontal to symphysis, ossified 

 and prolonged above into the mesethmoid, and com- 

 pletely separating the nasal chambers from each 

 other, its surface and upper border have a honeycomb 

 appearance. The premaxillary beak with a moderate 

 slope downwards, width at base ly% inch, length of 

 sjnnphysis 2^ inches; dorsal surface of frontal narrow 

 and extends backward between the parietals, marked 

 on the surface by a longitudinal groove. The squa- 

 moso-zygomatic process is massive, 5^ inches long by 

 2 1 high : the outer surface is somewhat concave, 



