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Show 1890.] MR. R. LYDEKKER ON A CERVINE JAW. 603 crowns, with a very bold internal cingulum, rising between the two inner columns into a flattened triangular accessory column. On the outer or external aspect these teeth are remarkable for the excessive development of the oblique ridges forming the lateral borders of the outer columns, or crescents, so that distinct cavities are produced on the outer surface by the reflection of these bordering ridges. The antero-external extremity of the second inner crescent runs up nearly to the extremity of the interval between the outer crescents after the fashion of the Cervidce. The premolars are likewise characterized by the strong development of the internal cingulum, and the reflection of the lateral ridges of the external surface of the outer crescent. From the general characters of the teeth, as detailed above, more especially the brachydontism of the crowns, the form of the inner accessory column, and the outward extension of the antero-internal angle of the second inner crescent, I have no doubt that the specimen is referable to one of the Cervidce. It indicates a Stag of somewhat smaller dimensions than Cervus cashmirianus. N o existing species of Cervus that has come under my observation has teeth with the large inner cingulum and complex outer surface which characterizes the present specimen. I have, indeed, found a few isolated teeth of the extinct C.giganteus, as exemplified by specimens in the Natural History Museum, presenting an inner cingulum approximating to that found in the molars of the jaw under consideration; but such teeth do not show the ' pocketed ' external surface found in the fossil molars. The nearest approach to the latter feature that I have observed occurs in the molars of some of the larger species of the Rusine group of the genus Cervus ; but all the members of that group are widely differentiated from the fossil by their hypsodontism. In the memoirs of Monsieur P. Thomas on the Fossil Mammals of Algeria, published in the M e m . Soc. Geol. France and elsewhere, there is no mention of any teeth like those of the specimen before us, nor indeed is there any species of Cervus described from the later Tertiaries of Algeria. Seeing, then, that the specimen under consideration appears to indicate a species decidedly specifically distinct from all existing Cervidce, and which cannot be identified with any fossil form known to me, I may be justified in regarding it, at least provisionally, as representing a new species, for which I propose the name of Cervus algericus. This species may be defined as follows :- Somewhat smaller in size than Cervus cashmirianus, with brachy-dont molars, having a very large inner cingulum, and the external surface complicated by the excessive development and reflection of the lateral ridges of the outer crescents so as to form distinct pockets on this surface at the base of the ridges in question. The teeth of this specimen appear to represent the most complex type of brachydont and selenodont molars yet described; and I venture to hope that the description of this specimen may lead |
