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Show 1885.] DR. ST. G. M1VART ON THE ARCTOIDEA. 363 indeed it is relatively broader than in any Arctoid yet here noticed. It has two external cusps and one internal cusp, and also an external and an internal cingulum, a small extra cusp being developed upon the latter. The second true molar is tricuspid, and also has its transverse diameter in excess. The lower teeth are like those of Procyon, only the first inferior molar has its middle external cusp more predominant in height, so giving that tooth a sectorial character. There is no caecum, and there is an os penis of considerable size. Bassaricyon \-This genus is only known by a skull collected by Prof. Gabb at Costa Rica, described and figured by Mr. J. L. Allen in the Proc. Acad. Phil, as B. gabbi, and by a skin and skull of a second species from Ecuador, described and figured by M r . Oldfield Thomas under the name of B. alleni. The external appearance of the first species is quite unknown. That of the second species is, as Mr. Thomas has pointed out, extraordinarily like that of the Kinkajou 2, so that, but for the skull, " no one could have believed that it was anything but a rather small specimen of that animal." The tail, however, does not seem to be prehensile. There are two mammae placed far back in the abdomen. The skull is more like that of Procyon and Nasua than of Bassaris. Its general profile is much like that of Procyon; but the orbits are very large, and the postorbital processes of the frontal more developed. There are none from the malar. The temporal ridges are widely separated. The palate is flat, extending much behind the last molars, where it is much narrowed; and the bony floor to the orbit (formed by the malar and maxilla) is very large, and the postorbital processes of the frontals are as long almost as those of Bassaris. Molar formula=P. \, M . \. The teeth are not sectorial, the molars being shorter and more nearly square than in either Nasua or Procyon, though in one species the second upper true molar is subtriangular as in Procyon. A cast of the inside of the skull shows that the brain possesses an Ursine lozenge3. Melesi.- \t would be superfluous to say anything here respecting 1 See Biol. Oentr. Am. p. 70; also Allen, Proc. Acad. Phil. 1876, p. 21, pi. i.; and Bull. U. S. Geol. Survey, v. p. 169; also Oldfield Thomas, P. Z. S. 1880, p. 397, pi. xxxviii. 2 Mr. Thomas says:-" The external resemblance of this species to Cercoleptes certainly seems to be an instance of mimicry, which, so common amongst insects, is so rare among Mammalia. It is, however, very difficult to understand how being mistaken for Cercoleptes could in any way benefit Bassaricyon; but when more of the habits are knowu, we may be able to guess at the true use of the likeness. Unfortunately no special notice was taken of the animal by the collector, Mr. Buckley, " as both he and the Indians thought it to be merely the common Kinkajou." 3 See the paper before referred to, p. 13. 4 See Linn. Syst. Nat. xii. p. 70; Schreber, iii. p. 516, pi. 142; Pallas, Zoo-graph, i. p. 7 0; Buffon, vii. p. 104, pis. 7-10; F. Cuv. M a m m . ii. 36 livr.; Wagner, Suppl. ii. p. 180; P. Gervais, Mammiferes, ii. p. 101; Bell, Brit. Quad. p 122; D e Blainville, Ost^ographie, Subursus; Chatin, Ann. des Sc. Nat. (5e serie) vol. xix. (1874) p. 106, figs. 65, 66, & 67 (anal glands and caudal pouch). |
