KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 48. w:o 5, 163 
The length of the horns of my two Waterbucks is, measured along the anterior 
curve, about 57—58 em., and two other bucks shot for trophies by Mr. Ss6qRrmEn 
near the same place had exactly the same length of the horns so that this measure- 
ment appears to be the »normal» at Guaso Nyiri below Chanler Falls, but the spread 
of the horns varies considerably. It was in these four bucks about 22 '/s, 27 ‘/s, 29, 
and 32 em. 
The measurements of the typical skull of K. e. thike is a little larger than the 
Guaso Nyiri skulls the basal length being 349 mm. according to Marsouie (I. ¢. p. 
411), and the greatest breadth 162 mm. The distance between the posterior surface 
of the occipital condyle and the anterior margin of the orbit is in Marscuin’s type 
specimen 185 mm. >also nur 23 mm. linger als die grésste Breite des Schadels». 
Martscute lays much stress upon the great breadth of the skull of K. e. thika, and 
he appears to regard this as a typical characteristic of that animal. If a comparison 
is made between the basal length of the skull and its greatest breadth, the latter 
measurement is found to be 46 °/o of the former according to MATscHIn’s measure- 
ments of K. e. thike. In a similar way the corresponding percentages for the skulls 
of my two Waterbucks from Guaso Nyiri prove to be resp. 46, and 47, and the 
difference between the greatest breadth of the skull and the distance between the 
occipital condyle and the front margin of the orbit is resp. 25 and 19 mm. But 
this great relative breadth of the skull is nothing characteristic of the northern 
Waterbucks of the ellipsiprymnus group alone. The measurements of a skull of a 
Waterbuck from South Africa recorded above show that the breadth of the same is 
46 °/o of the basal length there as well. These proportions are thus alike in southern 
as well as in northern specimens. 
To judge from Marscuir’s measurements of the typical skull of K. e. thike it 
appears to be a little larger than my two skulls from Guaso Nyiri but the difference 
is not great and might easily be individual. For the present no other cranial diffe- 
rences of importance can be pointed out, and it is thus rather uncertain whether 
the differences in colour and pattern justify the creation of a different subspecies 
for the Waterbucks of the Guaso Nyiri district. Against Marscure’s formal decla- 
ration it is, however, difficult for the present to identify his very dark K. e. thike 
with my pale specimens from Guaso Nyiri, and although unwillingly I have felt 
myself compelled to give them a separate name until the question can be fully solved 
by more material. 
The paleness of the Waterbucks along Guaso Nyiri appears to reach its extreme 
in some individuals at and near the Lorian Swamp, where I heard that »white Wa- 
terbucks> had been repeatedly observed. Such a one is reported in Proc. Zool. Soc. 
London 1905 II p. 297, and in »The Field» the »white Waterbucks» from this loca- 
lity have been mentioned more than once, and it has been stated that the eyes of 
these white specimens are »of the normal colour, not pink».* This makes this white 
variation to something more than the common pathological pink-eyed albino which 
now and then occurs among many different species of mammals. 
a Conf. also the Extract in The Journal of the East Africa and Uganda Nat. Hist. Soc. Vol. Il, N:o 3, p. 75. 
