BUSHBUCKS, KOODOOS, AND ELANDS 423 
liable guide to the natural affinities of the various species. 
A careful study of the skulls, however, reveals some impor¬ 
tant differences between species which have hitherto been 
combined in the same genus on account of horn resemblances 
solely. The genus of the koodoos, Strepsiceros , is an in¬ 
stance of this sort. The lesser koodoo, Strepsiceros im- 
berbis , is without doubt as closely allied to the bushbuck, 
Tragelaphus , as to the greater koodoo, as regards its skull 
characters and pattern of coloration. It is a geographical 
associate of both genera and deserves recognition as a 
separate genus in order to emphasize its true relationships. 
The nyala, Tragelaphus angasi, is another species which 
also must be accorded generic rank. Here, however, we 
have to do with a species showing almost identical horn 
characters with Tragelaphus , but differing distinctly in 
skull characters, pattern of coloration, and habits. 
The tragelaphine antelopes range over Africa south of 
the Sahara, from the northern limits of the Abyssinian high¬ 
lands and adjacent Red Sea coast south to the Cape. They 
are universally distributed throughout plains, forests, and 
swamps from sea-level to timber-line or the limits of forest 
growth. Geologically the subfamily is known as far back as 
the Miocene. Most of the fossil species are Eurasian and 
North African. Recently twisted horn-cores resembling 
those of the koodoo have been found by Merriam in the 
Pliocene of Nevada, but such forms were doubtful members 
of the tragelaphine group. Within the present year Gidley 
has described from a series of teeth from Pleistocene cave 
deposits in Maryland an American species of eland. It is, 
however, far from proven that the animal to which these teeth 
belonged was an eland or a member of the Tragelaphinee, 
