as in Mr. Reed's specimen. On the other hand, considerable portions of the enamel have been chipped off from the inner edge of the crown, while in the latter, which was derived from a younger animal, the crown is absolutely perfect.
Having compared Mr. Canham's tooth with the corresponding one of the original specimen of Hyænarctos sivalensis, Falc. & Cautl., from the Sewalik Hills, now in the British Museum, I can detect no appreciable difference—certainly none which would warrant, in the absence of other evidence, the imposition of a new specific name. The dimensions are identical; and so are the general contours of the margins, and the form and position of the cusps. At first sight a considerable difference is apparent in the outline of the inner edge, as seen when looking down on the grinding-surface; but this arises from the defective condition of the enamel noticed above, portions both of the anterior and posterior angles of the inner border having been lost, and giving the appearance of an angular rather than straight inner margin. The Sewalik animal was older, and the tooth more worn, which may account for the absence, or, at all events, less distinct evidence of the fine striation of the surface of the enamel, in lines converging to the apices of the cusps, which is beautifully seen in both the Crag teeth.
The Sewalik specimen was first described by Cautley and Falconer, in the 'Asiatic Researches,' vol. xix. p. 193 (1836), under the name of Ursus sivalensis; and it is certainly very closely allied to the true bears, though in its dentition somewhat less specialized than the modern representatives of the group. It has no particular affinity with Hyæna, as the name by which it is now generally known might be supposed to indicate. In an unpublished plate of the 'Fauna Antiqua Sivalensis,' executed about 1848, the species is designated Ursus (subgenus Hyænarctos) sivalensis[1]; and the same name must have been used by Falconer and Cautley before that date, as it is quoted in Owen's 'Odontography,' p. 503 (1845), although in 1842 Dr. Falconer objected to Blainville's proposed removal of the animal from the genus Ursus[2]. In 1837 Wagner gave the name of Agriotherium, and in 1841 Blainville both Amphiarctos and Sivalarctos, to Ursus sivalensis; so that, strictly speaking, all of these names have the priority to Falconer's; but, as Gervais remarks, "toutefois le mot Hyænarctos a prévalu." It is adopted in Pictet's 'Traité de Paléontologie,' vol. i. p. 18.
Remains of an animal of the same genus have been found in the Pliocene marine sands of Montpellier, and described and figured by Gervais[3] under the name of Hyænarctos insignis, though the specific distinctions between them and those from the Sewalik Hills are not very striking. As I found by direct comparison in the Paris Museum, the first true molar differs from the Crag teeth in having the two inner cusps more distinctly separated, instead of constituting an
