62 Bulletin American Museum of Natural History. [Vol. XXXIV, 
posed of but two cusps, pa? and pr’, which form a high crescent like that 
of the trigonid of m:, differing in the absence of metaconid and heel. A 
strong internal and posterointernal cingulum is the only trace left of the heel. 
G 
SAS 
Fig. 52. 
Fig. 52. Ambloctonus hyenoides, lower jaw, outer view, and crown and inner views of 
teeth, dps-s, mi-2, natural size. Type specimen, upper (Largo) horizon, Wasatch formation, 
San Juan Basin. 
Fig. 53. Ambloctonus hyenoides, jaw fragment from the Big Horn Basin, Wyoming, 
Lost Cabin beds. Natural size, external view and crown view of last milk molar and first 
true molar. - 
The paratype shows that the shearing action on m, was imperfect; mp 
in spite of its smaller size, appears to be the real carnassial or principal 
shearing tooth, as m! certainly is in the upper jaw. The cusp-construction 
of m3, similar in many respects to that of . of the hyzena, together with 
the large robust crowded premolars, suggest the specific name. 
Ambloctonus coloradensis (Matthew 1909). 
Patriofelis ulta Osporn 1897, Bull. A. M. N. H., Vol. IX, p. 256; 1900, zbid., 
Volo XU, p-278, fie. 8. 
Patriofelis coloradensis Marrurw 1909, Bull. U.S. G. S., 361, p. 96; Mem. A.M. 
N. H., Vel. Vi, p. 482. 
