108 BULLETIN 99, UNITED STATES NATIONAL MUSEUM. 
1910. Kobus defassa angusticeps Matscuig, Sitz.-ber. Ges. nat. Freunde Berlin, 
p. 416. (Laikipia Plateau, north of Lake Baringo, British East Africa; 
type in Powell-Cotton coll.) 
1914. Kobus defassa tjaderi RoosevEtt AND HewiEr, Life-Hist. African Game 
Anim., vol. 2, p. 500. 
Specimens.—Two, from localities as follows: 
British Hast Arrica: Lake Naivasha, 1 (K. Roosevelt); upper 
Southern Guaso Nyiro River, south of Lake Naivasha, 1 odd skull 
(Mearns). 
KOBUS DEFASSA RAINEYI Heller. 
Plates 43, 44, 45. 
1913. Kobus defassa raineyt HELLER, Smithsonian Misc. Coll., vol. 61, No. 13, p. 5. 
September 16. (Amala River, British East Africa; type in U.S. Nationa 
Museum.) 
1914. Kobus defassa raineyi Roosevett AND Heuer, Life-Hist. African Game 
Anim., vol. 2, p. 498. 
Specimens.—Six, from localities as follows: 
BritisH East Arrica: Kabalolot Hill, 1 odd skull (Rainey) ; Loita 
Plains, 1 odd skull (Rainey); Telek River, 4 (Rainey). 
If the Kobus adolfi-friderici of Matschie, 1906,’ described from the 
upper Orangi River, near the Massai Steppe, south of Ikoma, Ger- 
man East Africa, should prove beyond doubt to be a member of 
the defassa group, then this name should unquestionably take the 
place of Kobus defassa raineyi Heller. The two type localities are 
close together and specimens of the same species from each place 
are usually indistinguishable. There is, however, apparently some 
doubt as to the specific identity of adolfi-frideric: as the description 
is based on the head alone, and the two waterbucks, defassa and 
ellipsiprymnus, are, in very many cases, not surely identifiable by 
characters of the skull and horns. The common waterbuck (Kobus 
ellipsiprymnus) has, moreover, been recorded as reaching, at its most 
westerly point of distribution in central Africa, the region of the 
Serengeti Plains, near Ikoma. The form described as adolfi-friderici 
is with little doubt merely a geographical race of one of the two 
widely distributed species, ellipsiprymnus or defassa, but until its 
specific relationship shall be settled beyond doubt it seems better to 
list the above specimens under Kobus defassa raineyi, of which pro- 
posed race all are virtually topotypes. Lydekker, in 1908,? con- 
sidered adolfi-friderict a subspecies of ellipsiprymnus, but in 1914," 
he lists it among the forms of defassa. 
Other described forms of the Kobus defassa group, all from Abys- 
sinia and German East Africa, and not represented by specimens in 
the collections of the United States National Museum, are as follows: 
1 “Weidwerk in Wort und Bild, vol. 15, p. 234. April 1, 1906.” 
2 Game Animals of Africa, p. 196. 1908. 
3 Cat. Ungulate Mamm. Brit. Mus., vol. 2, p. 235. 1914. 
