592 GEOLOGICAL SURVEY OF THE TERRITORIES. 



teeth, covered with smooth and shining enamel. The anterior median 

 small tubercle of the first true molar is wanting. The last true molar 

 has but one interior cone. 



The canine tooth is ]iowerful and bear-like ; the outer incisor is the 

 largest. The premaxillary bones are short, and the side of the face 

 elevated and i>lnne to the convex nasal bones. The nasal bones are 

 long, narrow, and convex. Zygomatic arch massive. 



3Ieasurements. 



M. 



Leiigtb molar series, (No. 1) 0. 140 



Length truo molars 085 



LeugtU three incisors 034 



Length crown canine 0:50 



Length crown last molar 039 



Width cn)wu last liiplar 03G 



Length cranium to occipital crest 345 



Length true molars, (No. 2) 101 



Length last molars, (No. 2, ) (oblique) 039 



Width last molars, (Ko. 2,) (transverse) 038 



Pal^osyops major, Leidy. 



Survey of Wj-oming, 1871, y>. 359. Limiwhyus roiustus, Marsh, Amer. Journ. Science 



and Arts, 1872, p. 124. 



Numerous specimens from Cottonwood Creek, Black's Fork, Bitter 

 Creek, &c. 



PALiEOSY'OPS VALLIDENS, Cope. 

 Proceed. Amer. Philos. Society, 1872, p. 487, published August 22, 1872. 



Represented by the dentition of one maxillary bone with other bones 

 of one individual; a portion of the same dentition of a second; with 

 both rami of the mandible, with complete dentition, of a third. The spe- 

 cies is distinguished by the details of the dental structure, and by the 

 superior size. It exceeds, in this respect, the Pakcosyops major, Leidy ; 

 while the three posterior lower molars measure 4.25 inches in length, 

 the same teeth of the present animal measure 5 inches. The last 

 superior molar of another specimen measures 2 inches in length ; in the 

 third the first true molar is 1.5 inch in length, while the last inferior 

 molar is 2.25 inches long. The peculiarity in the structure of the supe- 

 rior molars consists in the existence of two strong transverse ridges, 

 which conue(;t the inner tubercle with the outer crescents, inclosing a 

 pit between them. These are most marked on the premolars, where 

 also is found the peculiarity of the almost entire fusion of the outer 

 crescents into a single ridge. These united crescents are narrower than 

 in P. major, and the summits of all the crescents are relatively more 

 elevated. The number of inner tubercles is the same as in that species; 

 all the teeth have very strong basal cingula, which rise up on the inner 

 tubercle. The inferioV molars are relatively narrower than in P. major, 

 and the posterior tubercle of the last is larger and longer, and is an 

 elevated cone. The inner tubercles in all the lower molars have broader 

 bases and less acumiuation. 



The bones containing the maxillary and mandibular teeth were not 

 found together in any instance, so that it is possible that the different 

 series may represent difi'erent species. No other species of the genus 

 was, however, found in the localities to which the resi)ective parts could 

 be referred. Should these prove not to pertain together, the lower jaws 

 may be regarded as typictd of the species. 



Found in the Mammoth Buttes, on South Bitter Creek. 



