74 CATALOGUE OF UNGULATES 



Distribution approximately co-extensive with that of sub- 

 family, except that it does not inchide North Africa, Arabia, 

 or Peninsular India. " Hoi arctic region from Cyprus and 

 Asia Minor eastward across central and northern Asia, and 

 in western North America from Alaska to northern Mexico ; 

 one species isolated in the Mediterranean portion of 

 Europe."— (M7/cr.) 



The following is a tentative " key " to the six species of 

 the genus here recognised : — 



A. Horns " perverted " ; females hornless. 



Size small or medium ; colour rufous, with a 

 light saddle-patch, at least in winter ; tail 

 black at tip 0. orientalis, 



B. Horns generally normal, but sometimes "per- 



verted" ; females horned or hornless. 



Size small (27 in.) ; colour dark, with a light 

 saddle-patch in adult rams in winter ; upper 

 side of tail black 0. niusimon. 



c. Horns normal {i.e. without " perversion"). 



a. Horns strongly wrinkled, with varying develop- 

 ment of front outer angle ; face-gland and 

 lachrymal pit large. 

 a' . Size medium (32 to 36 in. at shoulder), a long- 

 haired and generally partially or wholly 

 black throat-ruff, typically composed of 

 two lobes at base ; no nuchal or dorsal 

 crest ; tail short (4 in.) ; tips of horns 

 turning mainly inwards. 



a". Colour greyish or brownish fawn 0. vignei. 



b". Colour darker, with a double light saddle- 

 patch 0. laristanica, 



h'. Size typically very large (46 to 48 in.) at 

 shoulder) ; throat-ruff, when present, 

 wholly white, yellowish, or greyish ; 

 generally a dark nuchal, and sometimes 

 a dorsal, crest ; tail very short (3 in.) ; 



tips of horns markedly everted 0. ammon. 



h. Horns nearly smooth (apart from lines of growth) , 

 with front outer angles strongly pronounced ; 

 face-gland and lachrymal pit small. 

 Size large (39 to 40 in.) ; colour ranging from 

 black to white, with a large white rump- 

 patch in dark forms 0. canadensis. 



