1915.| Matthew and Granger, Lower Eocene Wasatch and Wind River Faunas. Gi. 
genus, as are the other premolars in number and form. M, is constructed 
as in Paleonictis occidentalis, but the heel is higher. Me differs in the 
absence of metaconid, but is quite as large as in P. occidentalis. The upper 
teeth compare closely with that species except for m? which in the type is 
buried in the jaw but in No. 16116 is a small transverse two-rooted tooth 
with a moderately large parastyle, little extended, a strong paracone, 
vestigial metacone, and compressed transversely trenchant protocone. 
‘The zygomatic arches are deep, wide and short, the sagittal crest thick and 
low. 
Fragments of the humerus and ulna indicate a construction similar to 
Oxyena but shorter and thicker proportions, and a relatively larger head. 
Ambloctonus sinosus Cope 1875. 
Ambloctonus sinosus Cork 1875, Syst. Cat. Vert. Eoc. New Mex., p. 7 (Apr. 17); 
1877, Ext. Vert. New Mex. Rep. U.S. G. 8S. 100th Mer., p. 91, pl. xxxiii; OsBporn & 
WortTMAN, 1892, Bull. A. M. N. H., Vol. IV, p. 106, fig. 8. 
Type, U.S. Nat. Mus. No. 2329, fragmentary upper and lower jaws and a few 
fragments of skeleton. 
A careful examination of the type specimen shows two small transversely 
set alveoli behind:m*, indicating a small transverse m~. The second lower 
molar has no metaconid, but the heel is a distinct high-pointed cusp with a 
heavy cingulum internal to it. 
The second specimen referred by Cope to “a sinosus is considerably 
larger than the type, and the second molar appears to have no heel. I 
have therefore transferred it to A. hyenoides. 
Ambloctonus hyznoides sp. nov. 
Type, No. 16215, a lower jaw with dp3_4 and m,_2. from the upper horizon of the 
New Mexican Wasatch. Paratype, U.S. Nat. Mus. No. 5377, lower jaw with ps-m, 
considerably worn, from the Wasatch of New Mexico. No. 16853, jaw fragment with 
dp.-m; from Lost Cabin horizon at head of Whistle Creek, Big Horn Basin, is also 
referred here. 
Specific characters: About one seventh larger than A. sinosus; m2 without heel. 
The molar teeth in the type are unworn, and show the peculiar con- 
struction very well. The three cusps of the trigonid on m; arg united by a 
sharp curving crest, the high hypoconid is also developed as a curved crest, 
a small crest projecting towards it from the metaconid separated by a narrow 
cleft and the inner heel cusp has disappeared. The tooth is essentially 
composed of two crescents concave inwardly. The second molar is com- 
