4 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 56 



Klipspringers were frequently seen on the Laikipia Plateau, 

 usually in small groups of two or three individuals. At one time 

 five were seen on the same hill, but this was probably a chance 

 gathering of two lots. None were seen on the Guas Ngishu Plateau. 



OUREBIA COTTONI Thomas 



Plate i, Fig. i, Skull 



Three skulls and head skins from south of the Nzoia River, on 

 the Guas Ngishu Plateau, June. These are practically topotypes 

 of cottoni, described from Sirgoit Rock, and show the species to be 

 very distinct from 0. kenyce, from the region northeast of Nairobi, 

 though closely related to 0. montana. From the latter it is, how- 

 ever, readily distinguished by the larger horns. The skins agree 

 with the series examined by Thomas in the absence of a distinct 

 dark frontal blaze. The skulls agree in all important measurements 

 and characters with the description of the type. They measure: 



155415 155420 155421 



Adult male. Young male Younji male. 



mm. mm. mm. 



Greatest length 168 165 163 



Condylobasal length 157 I55 I54 



Greatest breadth 7'^ 12> 7^ 



Interorbital breadth 54 45 40 



Muzzle to orbit , 87 85 85 



Upper tooth row 53 — ' — 



Length of horn 123 100 93 



* Last molars not entirely in place. 



OUREBIA MICRODON, new species 



Plate i, P'igs. 2, 3. Skill 



Type.—^kuW of adult male, Cat. No. 155422, U. S. N. M., col- 

 lected south of the Nzoia River on the Guas Ngishu Plateau, British 

 East Africa, summer of 1908. by John Jay White. 



Diagnostic characters. — Size large ; rostrum long ; teeth small ; 

 horns short, stout, and heavily ringed. 



Color. — External characters unknown. 



Skull and teeth. — Compared with skulls of O. cottoni the type 

 skull of O. microdon is much larger, with longer rostrum, narrow 

 interpterygoid fossa, and smaller teeth. Though the skull is larger, 

 the teeth are actually smaller. The basioccipital is nearly square, 

 with surface almost flat; very different from the deep-pitted, trian- 

 gular basioccipital of O. cottoni. From 0. montana it differs in 



