54 MAMMALIA. 



is mild and sociable ; they live in herds ; some having five 

 thousand in number are occasionally met with in Africa. 



GENUS CAPRA, Lin. Goat. 



Horns directed Upwards and backwards ; chin usually 

 furnished with a long beard ; forehead almost always con- 

 cave. 



GENUS Ovis, Lin. Sheep. 



Horns directed backwards, but inclining spirally more or 

 less forwards ; forehead generally convex; no beard. 



GENUS Bos, Lin. Ox. 



Horns directed laterally, inclining upwards or forwards in 

 the form of a crescent ; muzzle broad ; body short, thick and 

 high ; legs robust ; a dewlap ; nails behind the hoof. 



ORDER IX. CETACEA. 



The grand classical characters which nature has imprinted 

 on the cetaceous order will, in a philosophical view, vindicate 

 their arrangement among the Mammalia. Their internal 

 structure agrees, in every respect, with that of the Mammalia 

 of Cuvier ; and their external conformation also is in some 

 other parts similar. Being destitute of gills, they breathe by 

 means of lungs, which obliges them frequently to rise to the 

 surface of the water for fresh air. Another great resemblance 

 to the Mammalia is their having warm blood and being pro- 

 vided with mammse, with which they suckle their young, pro- 

 tecting them with parental attachment. 



Body fish-formed, terminated by a horizontal fin, in place 

 of posterior limbs. The anterior limbs likewise arranged as 

 fins ; toes enveloped in a covering, and without nails ; some 

 vestige of a pelvis, without articulation to the vertebral co- 

 lumn. 



The cervical portion of the dorsal spine very short; skin 

 smooth and more or less thick; no ears externally, nor movable 

 eyelids, nor lachrymal apparatus; eyes large; crystalline sur- 

 face very much convex ; habitation in the sea. Two fami- 

 lies. 



