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Show 1867.] DR. J. E. GRAY ON THE SKULLS OF THE FELID.F.. 259 nally, and has only a very slightly raised scarcely visible keeled ridge on that part. This process is represented as rather more prominent in M . de Blainville's figure of the skull (Oste'ographie, Felis, t. 9) than it is in the specimens in the British'Museum. The peculiarity in the formation of the skull, which separates the Lynxes from the Cats, is not very striking; but as it is common to the skulls of all the species of Lynxes, both from the eastern and western hemispheres, it shows how important it is to observe even slight differences. In the Felidce generally the upper processes of the intermaxillse and the front edge of the frontal bone on each side are provided with a more or less elongated conical process, which separates a part of the nasal from the maxilla; and in the Lynxes these processes are very slender and so much elongated that those of the intermaxilla and the frontals nearly or quite unite, and entirely separate the nasals from the upper front edge of the maxillee. This is not altogether peculiar to the Lynxes, the same structure being found in a Cat which has been called F. marmorata ; and the processes of the intermaxillary, often very long, reach up one-third the length of the side margin of the nasal in some of the larger Leopards. But the lateral processes of the frontal not being so long as in the Lynxes and F. marmorata, the two processes do not unite and separate the nasal bones from the maxillee as is found in all the species of the genus Lyncus. The skulls of the species of true Cats are so similar and uniform in their structure that they present very few tangible characters for the separation of the species into groups. In looking at a small series of skulls it is easy to perceive that some are remarkable for having a broad rather lengthened nose and moderate-sized orbits, and others a narrow, short nose, pinched up behind, and above with a more or less distinct concavity on the sides in front of the orbits, and the orbits generally large. The former structure is confined to the skulls of the larger species, as the Lion, Tiger, Leopard, Ounce; and the second is more marked in the small kinds. If a larger series of skulls is examined, the two forms gradually pass into each other, and it is found that the intermediate gradation of form occurs in the skulls of some of the species that are intermediate in size between the two extremes; while some of the skulls of the middle-sized species retain the characters of the larger broad-nosed species. In some species, while the skulls of the adult animals are similar to those of the larger broad nosed group, the skulls of the younger or half-grown specimens have the sides of the nose more or less concave and narrower behind, like those of the second group. The skull of a Chinese Leopard, presented by Dr. Lockhart, from Pekin, presents one of those anomalies in dentition which now and A then occur in most families of Mammalia. It has a small subcylindrical short tubercular grinder behind the flesh-tooth on one side of the lower jaw, and none on the other, thus having ou one side the formula of dentition that is peculiar to the genus Canis. But |
