1885.] DR. ST. G. MIVART ON THE ARCTOIDEA. 377 



below it is much flattened and everted. The angle is, however, 

 more conspicuous than in Arctonyx or Mydaus. 



Molar formula=P. g, M. ^. 



The fourth upper premolar is formed like that of the Civet. 

 The first upper true molar is very short but wide, more like that of 

 Ilycena than is the same tooth in any Arctoid yet here noticed. It 

 is, however, relatively wider within than without inwards. There 

 are two minute external tubercles and a yet smaller internal one, 

 within which is a large internal cingulum. The three inferior 

 premolars are much as in Males. The first lower true molar is very 

 sectorial, and not quite like any tooth as yet here described. It is 

 a good deal like that of the" Civet, with the talon reduced, or 

 like the front half of the same tooth in Meles, with only a 

 very small talon instead of the large one of the Badger. The 

 most anterior cusp is narrower than the one behind it, and their 

 adjacent margins form together an acute angle. The second true 

 lower molar is a small rounded tooth. The liver is very like that of 

 Nasua, but the part of the right central lobe which is on the left of 

 the gall-bladder is large. 



The brain ^ is very comjjlicated in its dorsal convolutions. The 

 Sylvian fissure is long and oblique and the anterior limb of the 

 Sylvian gyrus is very decidedly the narrower. There is a small 

 Ursine lozenge. The crucial and calloso-marginal sulci do not join, 

 a bridging convolution connecting the hippocampal and sagittal 

 gyri behind the crucial sulcus. 



" Orisonia ". — The Grison has a tail about half the length of its 

 slender body. The nose is destitute of any median groove and the 

 muzzle is rather acute. The eyes are short, broad, and rounded ; the 

 legs are short. The soles are naked, and locomotion is semiplanti- 

 grade. 



It inhabits Tropical and South America. 



There are 16 dorsal, 5 lumbar, 3 sacral, and 21 cervical vertebrae. 

 It has the relatively shortest Arctoid radius except Lutra. Com- 

 pared with the length of the head it has the broadest palate of any 

 Arctoid. 



The only cranial diflFerences from Galictis I observed were that 

 the foramen glenoideum is very small, instead of large, and that 

 the meatus auditorius externus is both long and very wide. 



The first cusp of the first lower molar is wide, and quite as wide 

 as the second, and their adjacent edges form an obtuse angle. 



The liver is like that of Galictis, but the left central lobe is smaller, 

 and the right central lobe is uniform in its diaphragmatic aspect. 



1 See I. c. pp. 15 & 16, figs. 4 & 5. 



^ See Schreber, Sang. p. 447, pi. 124; Tliimberg, Mem. Acad. St. Petersb. vi. 

 p. 401, pi. 13; Traill, Mem. Wern. Soc. iii. p. 437, pi. 19; Desmarest, Mam. 

 p. 175; Molina, Chile, iv. p. 258; Shaw, Gen. Zool. i. p. 4.33; Bell, Trans. 

 Zool. Soc. ii. p. 204, pi. 37; Buffon, H. N. Supp. iii. p. 170, pi. 25; Martin, P. Z. S. 

 1833, p. 140; Gray, P. Z. S. 1865, p. 122, Cat. Carniv. B. Mus. p. 99; De 

 Blainville, Osleog. Mustela; Waterhouse, Zool. of ' Beagle,' i. p. 21 ; Wagner, 

 Supp. ii. p. 215 ; P. Gervais, Mamm. ii. p. 110 ; Azara, Ess. i. p. 190. 



