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Show 280 PROF. HUXLEY ON THE CRANIAL AND [Apr. 6, inner cusp of both the upper and the lower sectorials (which measure not less than 28 millims. in length) obsolete, has no representative in the existing fauna. This fact is the more interesting, as the dentition of Paleeocyon, in some respects, presents a more thoroughly carnivorous aspect than that of the Old-World Wolves. Information respecting the Pliocene Canidae is scanty. One of the best-known forms is the Canis borbonidus (0. megamastoides of Pomcl), briefly described and figured by Gervais in the ' Paleonto-logie Frangaise' (ed. 2, p. 2\?<, pl. xxvii. fig. 7). An almost entire skeleton was obtained from the Pliocene of Cenle near Issoire. The skull is 150 millims. long; and Gervais justly observes that the ramus of the mandible resembles that of C. cancrivorus. From the figure I judge that the teeth were no less similar to those of this species. The humerus has an intercondyloid but no supracondyloid perforation ; and the digits are five in front and four behind. Opinions differ as to whether the deposits of (Eningen should be reckoned Lower Pliocene or Upper Miocene. The skull of the famous fossil Fox of (Eningen, originally described by Mantell, and subsequently made the type of a new genus, Galecynus, by Professor Owen, is unfortunately not in a sufficiently good state of preservation for the determination of the question whether it belongs to the Alopecoid or to the Thooid series. In its cranial and dental measurements it agrees with surprising closeness with the common Fox ; and this correspondence extends even to the form and dimensions of the left upper sectorial tooth, which I have recently found could be readily exposed for about half its length in the specimen preserved in the Geological Society's Museum. There is, however, a rather stronger indication of a secondary cusp on the anterior part of the base of the blade of this tooth than is usual in the Foxes. At present I fail to see any sufficient ground for placing this animal in a distinct genus from the Foxes. Considering the known amount of variation in the pollex of different Canidae, its slightly greater proportional length in the (Eningen skeleton, though an interesting fact in itself, can hardly be regarded as of much systematic importance. Much light has recently been thrown upon the palaeontological history of the Canidae by M . Filhol's * important researches upon the fossils of the phosphoritic deposits of Upper Eocene age in France, and especially upon tbe abundant remains of the genus Cgnodictis. Of these " viverrine Dogs," as M . Filhol calls them, he distinguishes no fewer than seventeen varieties, which shade off, on the one hand, into true Viverridae, and, on the other hand, into the Ampbicyonidae. M . Filhol has so fully described and so well figured examples of a large suite of specimens of the different forms of Cynodictis, that it is possible for those who have not enjoyed the opportunity of examining his materials to form an independent judgment as to the conclusions which may be drawn from them ; and on one or two points I venture to dissent from his views. 1 " Eecherches sur les phosphorites de Quercy," Bibliotheque de l'ficole des Hautes Etudes, xv. &xvi. 1876, 1877. |