14 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 60 



Female skulls lack the great development of the knobbed processes 

 of the basioccipital but the length of this latter bone is much less 

 than in the genus Redunca. The most closely allied genus is Re- 

 dunca, which differs chiefly in the long tympanic sheath, the greater 

 development of the knobbed processes of the basioccipital bone, 

 smaller orbit and wider and shorter lachrymal bone. 



The skull-differences between Oreodorcas and Redunca are quite 

 great notwithstanding the similarity of the general body-form, 

 pelage and horns, which give these two types a false appearance of 

 close kinship. 



The habits of Oreodorcas are strikingly different from those of 

 the swamp inhabiting Redunca. Its haunts are grassy or rocky hill- 

 sides, usually in close proximity to the haunts of the Klippspringer. 



In attempting to break up the sub-family Tragelaphinse into 

 natural genera, many difficulties are met with, owing to the absence 

 of appreciable structural characters among the species. The sub- 

 family is based chiefly upon the spiral twist of the horns. Accom- 

 panying this horn-character is a close similarity in shape of skull 

 and of the individual bones which compose it. The situation of the 

 foramina, fossa and sinuses is nearly the same throughout the group. 

 The teeth are also practically identical in shape and relative size. 

 The group may be defined as follows : Bovidce in which the males 

 are armed with spirally twisted horns, arising above the orbits and 

 extending backward and upward at an angle to the general dorsal 

 profile of the skull; horns of the female, when present, closely re- 

 sembling those of the male ; antiorbital fossa wanting ; lachrymal- 

 nasal sinus well-developed, but not enlarged ; lachrymal bone large, 

 the facial portion about equalling the orbit in size ; intraorbital fora- 

 men placed far forward, immediately in advance of the first pre- 

 molar, and on the maxillary canthus, the opening directed forward ; 

 cheek-teeth somewhat brachyodont and simple, the enamel fossets 

 not having accessory lobes ; body banded by transverse light stripes 

 or by spots formed by the breaking up of the striped pattern. 



Nearly all the species of the Tragelaphinse are so closely allied 

 that they might all be included in a single genus. Such an arrange- 

 ment would, however, result in considerable geographical confusion 

 and obscure the real relationships of the species. The attempt to 

 make genera of equal weight so as to express the relationships 

 clearly, or avoid confusion, results in a multiplicity of genera from 

 splitting into groups such closely allied species as those now under 

 consideration. The genera adopted by most writers are based almost 

 solely upon horn-characters. 



