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Show 1869.] MR. BLANFORD ON ABYSSINIAN SPECIES OF HYRAX. 641 in Euhyrax, being more than the length of the outer sides of the first three premolars, whilst in Hyrax 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 question be really of generic importance, it is remarkable that there are no external characters in addition; and, so far as m y own specimens enable m e to judge, the length of the diastema in Hy races is a very variable character. That it differs enormously with age is a matter of course, but I a m now speaking of adult skulls. In two from Adigrat, the lengths are as follows in decimals of an inch : - I. II. Length of diastema 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 ferruginous than the other, a character certainly of no importance. Other skulls show intermediate proportions in the length of parts of the jaw. I a m 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 generic rank. But, as I have already stated, m y knowledge of osteology is insufficient to enable m e 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 Hyrax 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. The following, therefore, appears to m e 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. (Dendrohyrax) dorsalis or an allied form. But the last identification is only based as yet on a figure of part of a skull. * In Cat. Cam., 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. |