1885.] DR. ST. G. MIVART ON THE ARCTOIDEA. 383 



its fore cusp much smaller, the Hyaena's being larger relatively than 

 in Felis. The relative proportions of the mid and hind cusps in 

 Gulo are much as in Rycena. The internal cusp is not so big 

 relatively as it is in Hijcena, though it is more like that of Hycena 

 than that of Felis. The first molar is a little larger than in Flycena, 

 which is intermediate between Gulo and Felis as regards the develop- 

 ment of this tooth. 



In the lower jaw the fourth premolar is less trilobed and the 

 principal lobe is less developed. The sectorial has a large heel. 

 There is a second true molar. 



Gulo compared with Cryptoprocta, Hyaena, and Felis. — In the 

 upper jaw the third premolar of Cryptoprocta is intermediate in form 

 between that of Felis and that of Gulo, but is more like that of the 

 former. The same is the case as regards the upper sectorial, both as 

 regards the three external cusps and the inner cusp. The first upper 

 molar of Cryptoprocta is also intermediate in its development, but is 

 much more Cat-like than Glutton-like. In the lower jaw the canine 

 of Cryptoprocta is more like that of Felis than is the case with the 

 canine of Hyana. The fourth premolar has a less trilobed crown 

 in Gulo than in Cryptoprocta. The sectorial has a small heel, but 

 not like that of Gulo, and the last genus alone of the three has a 

 second true molar. 



Gulo compared with Canis. — In the upper jaw the third premolar 

 is smaller, and has a smaller posterior cusp. The sectorial is very 

 like that of Canis, but the hindmost cusp is rather thicker trans- 

 versely. Gtdo has a much smaller first true molar and no second one. 



In the lower jaw, the fourth premolar is less trilobed, or rather 

 less quadricuspidate, this tooth of the Dog being much like that of 

 the HyiBna. The sectorial of Gulo has a smaller heel and the mid 

 cusp predominates less over the fore cusp. The second true molar 

 is much smaller and there is no third molar. 



The brain ' shows an elongated Ursine Inzenge. The cerebrum 

 is very wide posteriorly and its dorsal surface is much complicated, 

 the anterior Hmb of the sagittal gyrus being greatly expanded and 

 convoluted, while posteriorly it is medianly grooved. 



Tjutra ^. — The Otters, of which there are at least nine, pos- 

 sibly a dozen species (of very uniform coloration), are found over 

 all the geograpbical regions except the Australian. No species, 

 however, appears to be common to the Old and New Worlds. It is 

 therefore the most cosmopolitan genus of Arctoids we have yet met 

 with. The external characters of the genus are familiar, but it may 

 be noted that the muzzle has no central groove or only a trace of it at 



' See I. c. p. 17. 



- Erxleben, Syst. n. 448 ; Schreb. Saug. iii. p. 4.o7, pi. 126 a ; Desm. Mamm. 

 p. 188; Bell, Brit. Quad. p. 129; Buffon, Hist. Nat. vii. p. 134, pi. 11-17; 

 Wagner's Sup]i. ii. p. 249: P. Gervais, Marani. ii. p. 116; Cii-av, P. Z. S. 

 1865, p. 126 ; Oat. Carnivora B. Mus. p 100 ; De Blainville, Osteog.' Mustela ; 

 Linn. S. N. i. p. 6(i {Musfela Infra) : Pallas, Zoogr. i. p. 76 ( Viverra h'.fra). 

 Under this genus are also included Gray's genera Barangia, Lonfra, Nutria, 

 Lafronectes. Hydrogale, Latax, Pteronura. See Cat. Carnivora of Brit. Mus. 

 pp. 100-113. 



