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Show 1877.] ANATOMY OF THE RUMINANTS. 15 the interval between the canine tooth and the first premolar is cut away in all the true Ruminantia, and not in the Tragulidae, is interesting as a separating feature. In the Cervidae there is a difference from the Cavicornia in the arrangement of the region just in front of this. In the Sheep and its allies the median palatal process of each premaxillary bone extends back in the palatal region between the maxillae for some distance behind the most anterior portion of the facial surface of the maxillary bone, broadening as they go backwards for some distance, and then narrowing to a point somewhat abruptly. In no Deer which carries antlers have I found this arrangement, the median palatal processes of the praemaxillae in them being always slender (sometimes only incompletely developed), of uniform breadth, and terminating posteriorly at a point scarcely behind the line which joins the canine teeth. Both Moschus moschiferus and Hydropotes inermis agree with Oris in this respect, as does the Giraffe. Again, in the squamosal of the temporal there is a feature of value in the separation of the two major divisions of the typical Ruminantia. In the Cervidae this bone is deeper from above downwards than in the Bovidae ; in other words, the parieto-squamosal suture is situated nearer the upper border of the temporal fossa (more than halfway up it) in the former group, the general proportions produced by which are more easily recognized by inspection than from description. The squamosal of Moschus is oviform, that of Camelopar-dalis intermediate. Whilst comparing the skulls of the Cervidae which I have examined, the antlers have naturally attracted m y attention ; and many of their peculiarities seem to m e to be subject to definite laws. What may be called the typical antler is composed of a bifurcate beam, with a brow-antler springing from the front of its basal portion. These three parts may be termed A, B, and C, as in the accompanying diagram (see p. 16). They occur, uncomplicated, in the genus Rusa, in C. porcinus, C. axis, and C. alfredi (fig. 25. 1). On the assumption that most of the complicated many-pointed antlers that occur are the result of the exaggerated development of one or other or both of the extremities B and C, their special features may be explained. For instance, imagine that both B and C bifurcate, remaining of equal size, and we arrive at the condition found iu Cervus schomburgki (fig. 25. 2). C. duvaucelii differs in that B is extra-developed at the expense of C (fig. 25. 3), the latter often being not bifurcate, though sometimes so to a small extent. Following out the ingenious hypothesis of Mr. Blyth1, C. eldi only differs in the still greater development of the anterior of the branches of B (fig. 25. 4). With this last-named form C. virginianus and C. mexicanus agree, as does Rangifer tarandus, as far as its beam-branches are concerned. In Cervus dama, and in the species included in the genus Pseudaxis by Dr. Gray (C. sika, taevanus, and mantchuricus), a different condition maintains, B being reduced greatly and C correspondingly » P. Z. S. 1867, p. 835. |