KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 48. N:0 5. 



121 



Amhlyomma hebrceum (Koch) and Dermacentor rhinocerotis (De Geer)," In the ven- 

 tricle were found a few larvae of some Oestridce but they were too young to be 

 determined according to Prof. Sjostedt. 



The Rhinos in the Guaso Nyiri district had all, as far as could be observed, 

 small horns, the front horn measured along the anterior curve in those shot only 

 about 36—40 cm. 



According to several observers the Black Rhinoceros of the Somali countries 

 shall be smaller than those in other parts of Africa, and a subspecific name ssoma- 

 liensis^ was created in the year 1900 by Count J. Potocki. Drake-Brockman in 

 his book about »the Mammals of Somaliland»^ says »It has been said that it [the 

 Rhinoceros of Somaliland] is smaller than -the East African variety, but this is pos- 

 sibly due to the poorness of its food supply during certain seasons of the- year in 

 Somaliland. The horns certainly seldom grow to any great length » — — — (1. c. 

 p. 106). The Rhinoceroses north of Guaso Nyiri in the thornbush country live under 

 analogous conditions and they were certainly poor. The ribs could be traced through 

 the skin (PI. VII fig. 2). 



Quite recently Lydekker has compared two skulls of Drake-Brookman's 

 Rhinoceroses from Somaliland with a skull from »East Africa* and found ^ that the 

 former » differ by the narrower form of the whole upper surface, both at the inter- 

 parietal constriction and at the orbital expansion*. The figures of the Somali skull at 

 the side of the East African skull show a striking difference in breadth. Only two 

 measurements of the breadth of these skulls are recorded, viz. the » breadth at 

 orbits' and the ^zygomatic width*, in Lydekker's paper. For comparison the same 

 measurements of two South African, two East African, and two skulls from Guaso 

 Nyiri are recorded in the accompanying table of measurements. From this can be 

 seen that Lydekker's East African skull must have been unusually broad as none of 

 the 6 skulls now measured attain the same orbital breadth, nor zygomatic width. 



Length of upper aspect 



Breadth at orbits 



Zygomatic width 



Least width of skull at the postorbital 



constriction 



Width of across anterior horn boss . . 



Lydekkeb's 

 specimens 



Somali East Afr. 



cm. 

 57,5 

 23,0 

 29,5 



Guaso Nyiri 



cm. 

 55,5 

 27,5 

 35,6 



cm. 

 56,5 

 23,5 

 32,3 



11,8 

 13 



em. 

 54,5 

 21,7 

 31 



11,4 

 11,6 



Lydekker's East African skull is thus beyond the average in these respects 

 and accordingly, as this table of measurements indicates, the differences between 

 somaliensis and other Black Rhinoceroses are not so great as will appear from 



Ark. f. Zoologi Bd. 7 n:o 24 p. 4 Uppsala 1912. 



1 Conf. L. G. Neumann: Ixodides. 



2 London 1910. 



2 Proc. Zool. See. Londou 1911 p. 958- 



K. St. Vet. Akad. Handl. Band 48. N:o 5. 



-960. 



16 



