NO. 2 MAMMALS FROM BRITISH EAST AFRICA — HOLUST^R 5 



much larger size ; horns stouter and heavily ringed ; rostrum heavier ; 

 basioccipital square and flat. It may be distinguished from skulls 

 of O. kenyce by its larger size, longer rostrum and nasals, narrow 

 interpterygoid fossa, square and flat basioccipital; and shorter, 

 stouter, more heavily-ringed horns. The skull of O. microdon differs 

 also from skulls of all the above-mentioned species in the straight 

 line of the inner edge of the upper tooth row, which in all of these 

 is decidedly concave. The palate, therefore, is almost oblong, and 

 the distance across between the first premolars almost equals the 

 distance across between the last molars. 



Measurements. — See table below for measurements of the type 

 skull. 



Remarks. — As known from the skull alone this new oribi is very 

 different from O. cottoni, inhabiting the same region. It appears 

 to be more closely related to O. kenyce, from the headwaters of the 

 Tana River. 



A comparison of measurements of skulls of adult males of the 

 four species of Ourebia from the region is given in the following 

 table : 



O. microdon. O. coitoni. O. keriycB. O. montana. 



155422 I554IS 162857 I 12998 



Ourebia skulls. Guas Ngishu ^^ . „ „ ■ , tv, • . 



Adult males. Plateau. Guas Ngishu ^,^«ar 120 nn. east 



^ Plateau, Nairobi. of Lado. 



mm. mm. mm. mm. 



•Greatest length 175 168 165 164 



Condylobasal length 163 157 154 153 



Basal length 152 146 143 144 



Palatal length 98 94 88 89 



Greatest breadth 77 75 75 74 



Interorbital breadth 51 54 49 44 



Muzzle to orbit 95 87 85 86 



Length of nasals 60.5 61 51 58 



Upper tooth row 48 53 49 50 



Length of horn 108 123 115 102 



•Circumference of horn 55 50 4/ 47 



KOBUS DEFASSA UGANDA (Neumann) 



Skull and head skin of adult male, killed on the Guas Ngishu 

 Plateau, south of the Nzoia River, summer of 1908. The specimen 

 agrees with Neumann's description in its large size and colors, the 

 bright rufous face contrasting decidedly with the paler color of the 

 cheeks and neck. 



Measurements of the skull (No. 155414) are: Greatest length, 

 .420 millimeters; condylobasal length, 408; greatest breadth, 166; 



