6 



ARKIV FÖR BOTANIK. BAND 3. N:0 3. 



more reliable. Sunde VALii in describing O. cethiopicus drew 

 the attention to the fact that this latter animal had not as 

 O. afer an almost straight upper contour of the facial por- 

 tion of the sku]], but instead of 

 this a rather abrupt slope in front 

 of the eyes, or more precisely in the 

 posterior region of the nasals, after 

 which the contour again continues 

 in a straight hne. The Senegal Oryc- 

 teropus has this same shape of the 

 fronto-nasal portion of the skull still 

 more pronounced or »enoore plus 

 bombée» as Duvernoy writes (1. c. 

 p. 192). O. haussanus appears to be 

 similar to the last and O. erikssoni 

 belongs also in this respect to the 

 cethiopicus-senegalensis-grouip ^ as it 

 has the upper contour of the skull 

 strongly sloping in the fronto-nasal 

 region and then straight again in the 

 nasal. (fig. 1). This feature is also 

 perfectly visible on the photo of 

 the killed animal reproduced here. 

 O. erikssoni is through this character 

 very well distinguished from O. afer 

 but there are others as well. 



Fora men magnum has in O. eriks- 

 soni almost the same shape as in 

 O. afer or is perhaps still more trans- 

 versally oval, thus not round as in 

 O. cethiopicus. In O. haussanus it 

 is said to be oval but in the fossil 

 O. gaudryi the träns versal diameter 

 is comparatively longer^ than in 

 any of the recent species the fora- 

 men magnum of which has been de- 

 scribed . 



Fig. 1. Skull of O. erikssoni, 

 lateral view. V- nat. size. 



^ The skull of O wertheri is not known, but Professor Matsohie in- 

 forms me that it has the »Schnauze vor den Augen in der Mitte nicht 

 eingedriickt». It may therefore resemble O. afer in this respect. 



- Conf. the measurements recorded by Andrews. Proc. Zool. Soc. 

 1896 p. 298. 



