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Show 240 DR. PORSTTH MAJOR ON THE TOOTH OP AN" ANT-BEAR. [Mar. 14, " The anterior teeth, which O. Thomas l has shown to be premolars, are stouter and more numerous in the fossil than in the adult recent species, there being four premolars above and below, and, moreover, in the mandibula an eighth tooth, which, as to its position and shape, may be considered to be the homologue of a canine. In the upper jaw the anterior part of the snout is broken, but there must doubtless have existed a canine too. " The bones of the pes present no differences from those of the now living forms, with the exception of the first and fifth metatarsals, which are somewhat stouter in the fossil, a fact which leads to the supposition that there is in the recent Orycteropus a tendency towards the reduction of the digits. " Thus, on the whole, the fossil approaches closely its African congeners, and gives us no clue as to what might have been the ancestral form of the genus, which we place amongst the Edentates, there being no suitable place for it anywhere else. " There was a time when Marsupials, Edentates, Lemuroids, and Ratitae were considered as proofs of the former existence of an Antarctic continent, from which, their original home, they were believed to have spread northwards, peopling the various Continents in which they actually exist. Of late years, however, one after the other of these groups have been discovered in the Tertiary deposits of the Northern Hemispheres, in Europe and America. As regards the Slruthionidce, I have found in Samos a femur which can scarcely be distinguished from the same bone of the African Struthio. Remains of Struthio have, as is well known, likewise been stated, by A. Milne Edwards and Lydekker, to form part of the Siwalik fauna; and an egg of Struthio has been found iu Southern Russia (Gouvernement Cherson) 2. Therefore a more natural explanation of the present distribution of the groups above mentioned is to consider the southern points of the present continental masses as their last refuges, to which they have been driven by later invaders from the North3. " The presence of Orycteropus in the Ethiopian fauna had remained unexplained. The facts adduced this evening show that during the Upper Miocene representatives of this genus existed as far north and eastwards as the isle of Samos and Eastern Persia." The following papers were read:- 1 Oklfield Thomas, "On the Milk Dentition in Orycteropus? Proc. Eoy. Soc. London, vol. xlvii. 1890, pp. 246-248. 2 Struthiolithus chersonensis, Brandt. 3 Cf. Haacke (Biolog. Centralblatt, vi. p. 363). |
