Tliis large Paheotheroid is represented by parts of the two maxillary- 

 bones, which present the crowns of the third and fourth premolars, and 

 of the second and third true molars with the bases of the other molars 

 and premolars. 



Measurements. 



M. 



Length of entire molar series 0.1710 



" " true molars 1060 



'• " last molar (crown) 0420 



Width li " " " 0437 



■ Length second molar 0350 



" fourth premolar 0260 



Width " " 0260 



" third " 0200 



Length " '.' 0200 



Diameter of basis of canine 0263 



In comparing this species with P. paludosus, which also has the dental 

 crowns rugose, I have Dr. Leidy's descriptions of 1870* and '71. In the 

 first he describes a superior molar as "22 lines fore and aft, and 18 lines 

 transversely, " which measurement would nearly apply to the penultimate 

 of this species were the directions of the lengths exchanged. But 

 in the second description,! the true molars are said to measure " 3J 

 inches ' ' in length, which is nearly an inch less than in P. diaconus. 

 The species must therefore be different. In comparison with Marsh's 

 description of his P. laticeps, the measurements are all larger, and the 

 enamel is as rugose as in L. major, instead of smooth. The shortening 

 of the premolar series is greater in P. diaconus; thus in P. laticeps the 

 two sets of molars are related as 94 mm. to 61; in the present one, as 106 : 

 65; were the proportions similar, the length of the premolar series 

 should be 69 mm. 



From Henry's Fork of Green River. 



The species of this genus then are, in the order of size : P. diaconus, 

 Cope ; P. laticeps, Marsh ; P. paludosus, Leidy ; P. fontinalis, Cope- 

 There is however still some question as to the true position of P. pal- 

 udosus. 



Htrachyus implicatus. Cope, sp. nov. 

 This tapir is smaller and more slender than the H. agrestis, Leidy, but 

 exhibits an equal size of posterior molar teeth, which are thus relatively 

 larger than in that species. It is represented first, by both maxillary 

 bones with most of the molars complete, from Cottonwood Creek, Wyo- 

 ming ; then by the side of the face with molars of both jaws complete, 

 with symphysis and portions of all the incisors, from South Bitter Creek ; 

 and by part of mandibular ramus with teeth, from Green River, with 

 probably other specimens. 



* Proceedings Academy, Philadelphia, 1870, 113. 



t Hayden's Geological Survey of Wyoming. 1871, p. 359. 



