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Show 1028 DR. J. E. GRAY ON THE RHINOCEROTIDAE. [Dec. 12, There is a well stuffed young specimen of this species in the British Museum, and two skulls of adult and two of very young animals. In the Museum of the Royal College of Surgeons is a very fine adult skull of this species (no. 2960 a) with the two horns attached to the skin. It was obtained from Mr. Gordon Cumming's collection. It is 35 inches long from the end of the nasal to the occipital crest. The front horn is very long, slender, straight, and recurved; the front edge of the horn is worn by the animal rubbing it on the ground. De Blainville obtained, when he was in London, from Mr. Burchell the drawing of the head of this species (engraved in the ' Journ. de Physique') ; but the horns were added after it passed out of Burchell's hands, and are not the horns of the species. In the British Museum there are two skulls of very young animals of this species that were received with the adult skulls in the collection ; the milk-grinders are being formed, but could only just have been seen through the gums. The skulls are elongate, subcylindrical, and have a rounded nose, with a large nearly hemispherical prominence near the end of the upper surface for the support of the front horn. The grinders are very large compared with the size of the skulls, and occupy a great part of the cavity of the mouth ; the hinder one is placed in the centre of the length of the underside of the skull from the nose to the condyles. The larger of these young skulls (1003 b) is very like the smaller one, but there is a fourth grinder being developed behind the third one; it is not elevated above the edge of the alveolus, and has no smooth enamelled edge. The small first grinder is only very little more developed than in the smaller skull. The line of grinders occupies 6| inches. The intermaxillary bones are deficient. The palate ends, as in the smaller skull, in a line even with the back edge of the third grinder. The hinder part of the skull has lengthened more rapidly than the part in front of the edge of the palate. The nasal is slightly longer compared with the length of the skull than in the smaller specimen; they are 4^ inches long, the entire length being very nearly 14 inches-that is to say, nearly three-tenths of the entire length. The front of the nasal is more dilated on the sides, and becoming broader and more truncated as in the adult skulls. The lower jaw of this specimen is considerably longer than the other; and there is little difference in the state of the teeth, except that the second and third grinders on each side are higher out of the gums, rather more worn on the edge, and the first and fourth grinders are rather more developed and larger, the first on the two sides not being quite equally developed, but one more exposed than the other. The smaller specimen (1003 c) has three grinders appearing ; the smallest front one is least developed, hardly raised above the alveoli, and not showing any smooth enamel; the second and third grinders are nearly equally developed, the ridges being high and edged with enamel, the rest of the teeth are minutely rugulose; the hinder edge of the third grinder is on a line even with the front edge of the |