1869.] MR. BLANFORD ON ABYSSINIAN SPECIES OF HYRAX. 641 
in Euhyraz, being more than the length of the outer sides of the 
first three premolars, whilst in Hyraz it is less*. 
It is only with the greatest diffidence that I venture to offer an 
opinion on a subject with which I have so very small an acquaintance 
as osteology ; but I cannot help thinking that if the difference in ques- 
tion be really of generic importance, it is remarkable that there are no 
external characters in addition; and, so far as my own specimens 
enable me to judge, the length of the diastema in Hyraces is a very 
variable character. That it differs enormously with age is a matter 
of course, but I am now speaking of adult skulls. In two from 
Adigrat, the lengths are as follows in decimals of an inch : — 
I. II. 
Length of diastema ........ Be ee 0°35 0°45 
Length of first three premolars........ 0°48 0°48 
In these two, both aged specimens, the development of the teeth is 
precisely similar. The skins only differ in one being more ferrugi- 
nous than the other, a character certainly of no importance. Other 
skulls show intermediate proportions in the length of parts of the 
aw. 
: I am inclined to conclude that the differences pointed out by Dr. 
Gray may be of specific value, but that, where so much variation 
exists within the limits of a single species, it can scarcely take ge- 
nericrank. But, as I have already stated, my knowledge of osteology 
is insufficient to enable me to judge fully on this subject ; and as I 
may be falling into the not uncommon error of underestimating the 
importance of characters to which I have not given much study, I 
can only leave the matter in the hands of those better acquainted 
with them. Meantime, if the Shoa animal be really distinguishable 
from H. capensis, it will require a name. 
The only remaining observation I can add is, that, by examination 
of the specimens in both cases, I have ascertained that the species 
described by Dr. Gray as Hyrar burtoni is identical with the type 
in the Berlin Museum of Hemprich and Ehrenberg’s H. ruficeps 
vel dongolanus. As the former name is objectionable, the rufous 
head being apparently an individual peculiarity, I would suggest that 
the latter be retained. 
Tue following, therefore, appears to me to be the synonymy of the 
Hyraces hitherto described as inhabiting North-eastern Africa. 
The species indicated above may have to be added, and also, if Dr. 
Gray’s suggestion be correct, H. (Dendrohyraz) dorsalis or an allied 
form. But the last identification is only based as yet on a figure of 
part of a skull. 
* In Cat. Carn., Pachyd., and Edent. Mamm. in Brit. Mus. 1869, p. 289, Dr. 
Gray says, “in the H. brucei it (the diastema) is as long as the length of the outer 
sides of the first three premolars and the half of the fourth one ; in H. capensis 
it is only as long as the outer sides of the first two premolars and one-third of 
the third one.” From the context it is evident that H. brucei is a misprint for 
Euhyrax abyssinicus. I have not access at present to the ‘ Annals’ in which the 
description originally appeared. 
