1885.] DR. ST. G. MIVART ON THE ARCTOIDEA. 363 



indeed it is relatively broader than in any Arctoid yet here noticed. 

 It has two external cnsps and one internal cusp, and also an external 

 and an internal cingulum, a small extra cusp being developed upon 

 the latter. The second true raolar 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 

 moi'e 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. gabhi, and by a skin and skull of a 

 second species from Ecuador, described and figured by Mr. 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 -, 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 

 mammse placed far back in the abdomen. 



The skull is more like that of Procyon and Nasua than of Bas- 

 saris. 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. 



Molarformula=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 lozenge ^. 



Meles^.-^li would be superfluous to say anything here respecting 



' See Biol. Oentr. Am. p. 70 ; also Allen, Proc. Acad. Phil. 1876, p. 21, pi. i. ; 

 and BuU. U. S. Geol. Survey, v. p. 169 ; also Oldfield Thomas, P. Z. S. 1880, p. 

 397, pi. xxxviii. 



^ Mr. Thomas says: — "The external resemblance of this species to Cerco- 

 leptes certainly seems to be an instance of mimicry, which, so common amongst 

 insects, is so rare among Mammaha. It is, however, very difDcult to under- 

 stand how being mistaken for Cercolepfes could in any way benefit Bassaricyon ; 

 but when more of the habits are known, we may be able to guess at the true use 

 of the hkeness. 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." 



^ See the paper before referred to, p. 13. 



* See Linn. Syst. Nat. xii. p. 70 ; Schreber, iii. p. 516, pi. 142 ; Pallas, Zoo- 

 graph, i. p. 70 ; Buflbu, vii. p. 104, pis. 7-10 ; F. Cuv. Mamm. ii. 36 livr. ; 

 Wagner, Suppl. ii. p. ISO ; P. Gervais, Mammiferes, ii. p. 101 ; Bell, Brit. Quad. 

 p. 122 ; De Blainville, Osteographie, Subursus ; Chatin, Ann. des Sc. Nat. (be 

 s6rie) vol. xis, (1874) p. 106, figs. 65, 66, & 67 (anal glands and caudal pouch). 



