458 GEOLOGICAL SUKVEY OF THE TERRITOEIES. 



continiions dental series is characteristic of many genera of the Eocene. 

 In the only known species, there are no osseous tuberosities on the rami. 

 The symphyseal suture is persistent. 



Cliar. specif. — Last premolar with longer basis than first molar ; its 

 Ijosterior heel tubercularly plicate. The crown of the penultimate pre- 

 molar is a slightly-compressed cone with elongate base, but little shorter 

 than that of the first molar. Molars with smooth enamel; an anterior 

 cingulum on the second and third ; a small posterior median tubercle 

 on the second molar ; and a short cingulum, from the base of the poste- 

 rior cone forward, on the third. Canines very large, suberect; enamel 

 smooth. Eamus of mandible very stout. 



Measurements. 



M. 



Length of molar series 0. 180 



Diameter of caniue tootli 033 



Length of premolars 093 



Length of iireraolars No. 3 035 



Length of molar No. 1 024 



Length of molar No. 2 027 



Width of molar No. 2 022 



Length of molar No. 3 041 



Widthof molarNo. 3 '.. .024 



Depth of ramus at molar No. 2 ■. 073 



This species betrays more of suilline character than any yet discov- 

 ered in the Bridger series ; but that it has any such affiuity has yet to 

 be shown. It was about as large as a fully-grown cow. 



PHE]SACODUS, Cope. 



Paleontological Bulletin, No. 17, p. 3. 



Phenacodus prim^vus, Cope. 



Char, gen.., as expressed by a posterior superior molar tooth. Crown 

 transverse, a little narrower and more strongly convex at the inner than 

 the outer extremity. It supports five rather low and obtuse tubercles, 

 two exterior and three on the inner side. Outer tubercles well inside 

 the outer margin of the crown; the one subtriangular in section : the 

 other more nearly conical ; the two connected by a low ridge, which 

 incloses a concavity with the outer margin of the crowu. Three inner 

 tubercles, arranged on the segment of a circle, subequal ; the lateral of 

 one side connected with the exterior tubercle of the opposite side by a 

 low ridge, which incloses a basin with the inner tubercles. 



Char, specif. — Median of the three inner tubercles stouter than the 

 others. No noticeable basal cingulum. Two compressed roots, with 

 axes at right angles to each other, and very large pulp-cavities and thin 

 walls. 



Measurements. 



M. 



Widthof crowu 0.0140 



Length of crown 0093 



Elevation of outer cones above shoulder 0050 



Width between apices of outer cones 0060 



Width between apices of median cones 0050 



This tooth more nearly resembles the last tubercular molar of a 

 canine carnivore than any other with which I can compare it, though it 

 presents some differences. It would represent an animal rather larger 

 than a wolf. 



