294 



HYEACIDiB. 



molars and premolars, in a nearly straight Une, and the great length 

 of the diastema which is so characteristic of this section of the 

 genus. It may he the skull of the D. arboreus of South Africa. It 

 differs from the skuU of Z>. dorsalis in heing small, in the forehead 

 being convex in the centre between the orbits, and in the orbits 

 being incomplete behind. It has the alveoli of the upper cutting- 

 teeth each raised into a cup round the base of the tooth ; but this 

 may be only an individual peculiarity. 



This skull has aU the characters of the genus B&ndrdhyrax, ex- 

 cept that the orbit is incomplete behind. I think that it indicates 

 a new group, to which the name Heterohyraso may be given. The 

 skull is much smaller and the tooth-hne much shorter than in Z>. 

 dorsalis ; and I propose to name it provisionally Heterohyrax Blain- 

 villii. The skull which M. de BlainviUe figures as that of Hyrax 

 rufipes (Osteograph. t. 2) exactly represents the hinder part of that 

 in the Museum. It cannot be the H. rujke-ps of Ehrenberg, 



Dr. G. V. Jaeger figured, under the name of Hyrax Jiabessinieus 

 (t. 2. f. 14), the upper part of the skull of a Dendrohyrax obtained 

 from Gondar by Dr. von HeugUn. Dr. Jaeger, by mistake, figures 

 the upper edge of the occipital /or the interparietal. This skuU is 

 interesting as showing that the genus is found m Abyssinia. 



Dr. G. V. Jaeger also figures the back of the skuU and interparietal 

 bone of a species he calls Hyrax silvestris, collected in West Africa 

 by the missionary Dieterle. It is probably a Dendrohyrax. The 

 hinder part of the figure is the upper edge of the occipital. The 

 interparietal is urn-shaped, broader in front and contracted behind, 

 very unlike that found in the skulls of either of the two species in 

 the British Museum, and especially differing from D. dorsalis of 

 West Africa ; so it may be a new species of the genus, Dendrohyrax 

 silvestris (Wiirzb. naturw. Jahresb. xvi. p. 162, t. 2. f. 15). 



The Measurements of the Skulls, in inches and lines. 



^ 



r 







I?" 





IS 



,t-H 



.c- 



9^ 



3 

 1 



■si 



Length of skull 



„ ■ tooth-line. 



Width, at centre of] 

 zygoma, of fore- > 

 head J 



Width at back end of 1 

 orbit ', J 



Width of band atl 

 middle of crown > 

 over condyles ... J 



Width of nose 



„ at outer edge 1 

 of tooth-line, at > 

 first molar J 



Width of palate at? 

 first molar f 



4 



1 6 



2 21 

 1 7 



3 



7 



1 3 



7i 



3 7 



m 



2 0J 



1,8 



2 

 7 

 12 



7i 



3 6 

 1 6 



2,0J 

 1 6 



OJ 



8 



1 4 



8 



2 U 

 1 2 



1 3 



7 



6J 



1 OJ 



7 



1 8 

 12J 



6J 



7 



1 



6^ 



3 2 



1 8 



2 

 1 6 



n 8 



6i 



loj 



6J 



2 7i 



1 7 

 1 2 



6 

 lOi 



4 



1 7 



2 3 



1 9 



9 

 Bi 

 12i 



9 



3 4 



110 

 1 6i 



1 



7 



1 



2 1 



1 2J 

 1 



3 4 

 1 2J 



1 11 

 1 6J 

 10 



: 



Hi 



6 



