KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 48, N:0 5, 155 
Rhynchotragus guentheri wroughtoni Drake-BrockMan. 
Drake-Brockman: Ann. & Mag. Nat. Hist., Ser. 8. Vol. IV, p. 51. 
When the expedition had crossed Guaso Nyiri to tho northern side at the ford 
on the Marsabit road Dik-diks were found to be rather common in the thornbush, 
On the first and second days march towards the east from the ford mentioned I 
shot five specimens of a greyish looking Dik-dik with very short nasals and a well 
developed proboscis (Pl. XIV, fig. 1), evidently belonging to the Rhynchotragus 
guentheri group. This group which is characterised by the »tips of nasals about level 
with the back of the middle premolar» includes Rh. guentheri THomas with the sub- 
species Rh. g. smithi Tuomas and Rh. g. wroughtoni DRAKE-BRocKMAN, and Rh. naso- 
guitatus LONNBERG. My specimens from the northern side of Guaso Nyiri appear to 
differ rather strongly from all these, among other characteristics by their extremely 
short nasals which do not attain a maximum length of more than about 10 mm., 
and often less. The premaxillaries are very short and do not reach more than about 
half way to the nasals. In Rh. guentheri, as THoMas kindly has written to me, there 
is a small discontinuous remnant of the nasal process of the premaxillary left which 
reaches the nasal suture, but nothing like this can be seen in my specimens. The 
maxillaries again extend upwards in front of the lacrymale in the shape of a 4 to 6 
mm. broad band which forms a suture of a similar breadth with the nasals. The 
lacrymale is thus entirely excluded from the margin of the anterior nasal opening. 
In the fig. of the skull of Rh. guentheri in Proc. Zool. Soc., London 1894, p. 324’ 
the lacrymale excludes the maxillary from the nasals and I took this for an important 
difference, but THomas has in a letter kindly informed me that this figure is not 
quite correct. In reality the maxillary reaches the nasal with a short suture in Rh, 
guentheri. The discrepancy in this respect is thus not very important, but the dif- 
ference in length of the nasals prove completely the distinctness of my specimens 
from Rh. guentheri. The length of these bones is in the latter species 17—17,5 mm., 
but in my specimens from 8 to 10,3 mm. In addition to this there are also diffe- 
rences in colour which will be mentioned below. 
Rh. g. smithi THomMas was described’ on a head skin and a skull from Lake 
Stephanie. This skull resembles, according to a communication from the author quoted, 
with regard to the shortness of the premaxillary and the broad suture between max- 
illary and the nasal the skulls of my specimens. But Rh. g. smithi differs markedly 
from the latter with regard to size. Although the type skull is of a male, all its di- 
mensions are larger even than those of my biggest female skull, in spite of the fact 
that in these animals, as is well known, the females are always larger than the males. 
Compared with my male skulls the basicranial length of Rh. g. smithi is about 9 °o 
' Reproduced in Book of Antelopes, Vol. Il, p. 90. 
2 Proc. Zool. Soc., London 1900, p. 804. 
