BIKDS OF ETHIOPIA AND KENYA COLONY 193 



the White Nile south to Taufikia or thereabouts, and the north- 

 eastern Belgian Congo (Uelle district) west through Kordofan to 

 Darfur; (2) ahessmica, which occurs throughout the elevated por- 

 tions of Ethiopia and of British Somaliland, south through the 

 Mongalla Province of the Sudan, Turkanaland, and Uganda to the 

 Kuwenzori Mountains, east through the Elgon and north Kavirondo 

 districts to Mount Kenya and the highlands of the Kikuyu country 

 in Kenya Colony; (3) griseigula^ which is found in the lower plains 

 of northern Tanganyika Territory, east to the Kilimanjaro district, 

 north through the Teita district and the Taru area to the Tana 

 Valley, thence west to Marsabit and southern Kendile ; it will be seen 

 that in Kenya Colony this form occurs to the north, east, and south 

 of abessinica, while northwestern individuals of griseigula are sur- 

 rounded on the north and south by ahessinica, a state of affairs that 

 has caused much confusion among students of African birds, and 

 which is responsible for many misidentifications in published work, 

 (4) the coastal race, erlangerl; this form Sclater ^^ considers to be a 

 synonym of griseigula^ but in this I feel he is mistaken. These four 

 forms may be differentiated by means of the following characters, 

 but it should be remembered that the differences are average, not 

 absolute, in nature: The dorsal coloration (in adults) is gray, fairly 

 free of any brownish cast, in dbessinica and erlangeH; in griseigula 

 and hrevicaudata it is much washed with brownish. Of the first two, 

 with relatively pure grayish backs, erlangeri has the abdomen largely 

 pure white, and is small, wings 51 to 56 mm, while ahessinica has the 

 abdomen chiefly grayish, the white restricted to a small median area, 

 and is larger, wings 54 to 59 mm. The two races with brownish 

 backs may be told by the fact that gnseigula has the sides and flanks 

 washed with brownish, while in 'brevicaudata these parts are grayish. 

 As might be expected, in Kenya Colony many intermediates between 

 ahessinica and griseigula occur, and in northwestern Uganda and the 

 Mongalla area of the Sudan, intermediates between ahessinica and 

 hrevicavdata are found. 



Van Someren *" records Camaroptera hrevicaudata pileata from 

 Mombasa, Changamwe, Manda, and Lamu. These birds I think are 

 all erlangeri, as they have grayish-brown tails, while pileata, which 

 is a race of C. Irachyura and not of 0. hrevicaudata, has the tail 

 green. It happens that C. hracTiyura pileata occurs together with 

 C. hrevicaudata erlangeri at Mombasa, whence I have seen specimens 

 of both. 



In comparing specimens of ahessinica with others of griseigtda, 

 one must take care to choose wholly comparable individuals, as imma- 



** Systema avium ^thiopicarum, pt. 2, p. 544, 1930. 

 "Nov. Zool., vol. 29, p. 228, 1922. 



