10 CATALOGUE OF UNGULATES 



which the direction of the horns is forward. In the red 

 sheep {Ovis orientaUs), although the right horn still forms a 

 right-handed spiral, and the left horn a left-handed spiral, 

 the curves are differently directed, the tip of each horn 

 forming the summit of a downward instead of an upward 

 spiral. This variation, which also occurs in the bharal 

 (Fseudois nalioor) and the arui {Ammotrag^is Icrvia) among 

 sheep, and in the East Caucasian tur {Capra caucasica) 

 among goats, constitutes a "mathematical perversion," and 

 causes the horns to curve backwards behind the neck. 



The condition wdiere the right horn forms a riglit-handed 

 spiral is termed homonymous. In contrast to this is the 

 heteronymous condition, in which the right horn forms a 

 left-handed spiral and vice versa. This condition obtains in 

 existing antelopes. Most wild goats exhibit the same spiral 

 in their horns, and this condition also obtains in the 

 Circassian breed, but in other domesticated goats the spiral 

 runs in the reverse direction, that is to say the right horn 

 forms a right-handed spiral, as in sheep. Spirals of the 

 kudu and markhor type have been described as " twists," 

 and those of ordinary sheep (in which the horns are coiled, 

 instead of twisted on their own axis) as " curves ; " but the 

 horns of domesticated breeds of sheep show a transition from 

 one condition to the other. 



A. Horns homonymous. 



a. No face-glands or foot-glands ; upper molars 

 hvpsodont, with broad crowns and an 

 accessory column on inner side (fig. 2). 

 Teats 4. Horns in both sexes, not much 

 smaller in feixiales than in males, smooth 

 or wrinkled transversely, and set far 

 apart at or near vertex of skull. Muzzle 

 bare, moist, and undivided. Size gener- 

 ally large. Tail long and tufted Bovinw, p. 11. 



B. Horns homonymous or heteronymous. 



Face-glands and foot-glands present or absent ; 

 upper molars hypsodont, with narrow 

 crowns and no distinct inner accessory 

 column. Teats usually 2. Horns large, 

 generally much larger in males than in 

 females (in which they may be wanting), 

 nearly smooth, wrinkled, or knobbed 

 in front, set close together. Muzzle 

 narrow, hairy, and vertically grooved. 

 Tail usually short; never tufted Cajjrince, p. 72. 



