ROAN, SABLE, AND ORYX 325 



Nasal bones short, equalling or less than narial chamber in 

 length 

 Snout not elongated; tail well developed; horns long, 

 usually exceeding length of head; body size me- 

 dium; nasal bones longer, seldom less in length 

 than narial chamber Antilopina 



Snout elongated into a proboscis; tail rudimentary; horns 

 short, projecting straight back; body size small; 

 nasal bones very short, less than one-third 

 length of narial chamber Rhynchotragince 



Subfamily Egocerina 



SABLE, ROAN, AND ORYX ANTELOPES 



Both sexes of the members of this subfamily bear horns, 

 those carried by the female sex being somewhat more slender 

 but often no less in length than those of the male. The 

 horns are either curved evenly backward, as in the sable, 

 straight, as in the oryx, or spirally twisted, as in the addax. 

 The antelopes of this group are best characterized by their 

 large size, high withers, long ears, and absence of lachrymal 

 glands on the face. Other characters are the long, tufted 

 tail, maned neck, and striped face. The skull lacks an ante- 

 orbital fossa, or depression, owing to the absence of the lachry- 

 mal gland, but in most of the genera a small lachrymal-nasal 

 sinus is present. The teeth are very long and broad, with 

 well-marked accessory columns in some of the genera, being 

 similar to oxen in this respect. The skull, however, has the 

 long nasals and the slender snout similar to the hartebeest. 



The young are very differently colored from the adults, 

 being uniform fawn without any conspicuous markings. 



Key to the Genera 



Horns curved backward in a great semicircle, at their base arising 

 abruptly above the orbits Egoceros 



Horns straight or but slightly curved, projecting backward in line with 

 the face and arising behind the orbits 



Oryx 



