356 GEOLOGICAL SURVEY OF THE TEREITOEIES. 



half as large as the outer one. The notch of the sectorial border is 

 directed more forward than in the Fox, and does not terminate in a cleft. 

 The heel or back portion of the crown occupies nearly half its breadth 

 and incloses a cup-like concavity as in the Weasel. The breadth of the 

 crown of the two teeth is nearly the same, being 4 lines ; the height of 

 that of the premolar is 3J lines ; of that of the sectorial molar, 2f lines. 



Oanis. 



Canis montanus. 



Some remains from Grizzly Buttes, Wyoming, are described by Prof. 

 Marsh, and referred by him to a species of wolf under the above name. 

 It was larger than the existing Gray Wolf. 



YuLPAVUS, Marsh. 



Yulpavus palustris. 



An extinct carnivore, described by Prof. Marsh, from remains found 

 by Dr. Carter near Fort Bridger, Wyoming. The animal was smaller 

 than the Fox. 



mSEOTIVOEA. 



It was through Dr. J. Yan A. Carter's discovery of the remains of a 

 small insectivorous animal, in association with an abundance of frag- 

 ments of turtle-shells, in 1868, that our attention was first especially 

 directed to the Tertiary formation of Wyoming, which has since yielded 

 such an abundance of evidences of early mammalian life. 



Omomys. 

 Omomys Carteri. 



The remains, consisting of one side of the lower jaw- and portions 

 of the cranium, were found by Dr. Carter, imbedded in , a stratum of 

 green, friable sandstone, in the vicinity of Fort Bridger. The jaw and 

 its contained teeth indicate an animal apparently nearly related, if not 

 actually belonging, to the family of the Hedge-Hog. The specimen is 

 fully described and figured in " The Extinct Mammalian Fauna of Da- 

 kota and Nebraska," &c., p. 408, PI. xxix. Figs. 13 and 14. 



Pal^acodon. 



Falceacodon verus. 



Another insectivorous mammal, though probably a marsupial, like 

 the Opossum, is indicated by several specimens discovered the last sum- 

 mer by Dr. Carter, at Lodge-Pole Trail, Wyoming. One of the speci- 

 mens, a fragment of an upper jaw, contains a back-molar tooth, resem- 

 bling those of the Opossum, but having the outer lobes of its crown pro- 

 portionately better developed, and the intermediate ones reduced to a 

 minute condition. The other specimen, an isolated tooth, is a reduced 

 example of the former tooth. The larger tooth is 2 lines fore and aft 

 and 2^ lines transversely. The animal was about half the size of the 

 Opossum. 



