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Show 1885.] DR, ST. G. MIVART ON THE ARCTOIDEA. 361 Cynogale is 14*0, while in Lutra the relative dimension may descend to 10*5. The snout is upturned towards its tip, and the interorbital surface is swollen and convex, thus recalling to mind the form of the skull of Ailurus. The infraorbital foramen is very low down and distant from the orbital margin, and the maxilla forms but a very small bony floor to the orbit. The palate does not project back quite so far as the posterior ends of the last upper molars. The mastoid process is very large and lamellar. The glenoid fossa is enormously broad. The condyloid foramina are very small. The bulla is moderately swollen, as in Ailurus, but very small relatively. There is a glenoid foramen, more or less hidden, but no alisphenoid canal. The mandible is very like that of Ailurus, with a very high coronoid process, a small angle pressed upwards, and no suhangular process. Molar formula, P. |, M . •§. The premolars are two-rooted, except the first upper premolar, which is very minute. The second has three lobes, whereof the median is very much the largest. The third has three external and three internal cusps, with a sixth very small accessory cusp between the antero-internal and the antero-external cusps. The fourth premolar has three external and three internal cusps, with a minute accessory cusp between the two internal cusps and an internal cingulum. The first upper true molar, which has a square grinding-surface, has two great external cusps, with a rudimentary tubercle in front of the more anterior of the two; also two large internal cusps and a very distinct internal cingulum. The second upper true molar is a most exceptionally formed tooth, having a grinding-surface covered with a great many minute prominences at its hinder part, with two distinct and large external tubercles, and at least one internal tubercle at its anterior part, the whole being bordered within by a very distinct internal cingulum. The three inferior premolars increase in size equally and pretty regularly from before backwards, and the crown of each has three tubercles, the median tubercle becoming less predominant as the accessory tubercle increases in size from the first to the third premolar, those of the third being nearly equal-sized. The first lower true molar is like the corresponding tooth of Ailurus, with slight superadded complications, with a large antero-internal cusp, and only a single undivided postero-internal cusp. The second molar is only quadricuspid, with no posterior tubercle or talon, because there is here a third molar. This last tooth is a large, flattened, rounded tooth, with an irregular surface. The brain bears a large ursine lozenge1. Bassaris2.-This is a small American Arctoid genus, of slender form, with somewhat digitigrade feet and slender muzzle, but which 1 See the paper on the convolutions before referred to, p. 12. 2 There are two species-B. astuta from Ohio, Oregon, Texas, California, North Mexico, and Vera Cruz; and B. sumichrasti, from the mountains of Mexico, Central America, and Costa Rica. See Biol. Centr. Am. Mammalia, p. 71, pi. vii.; Abh. Ak. Berlin, 1827, p. 119; (Wagler,) Isis, 1831, pp. 423 and 513; Water- |