1881.] Geology and Paleontology. 669° 
nivora» 1 may add that in 7Zriisodon the inferior border of the 
lower jaw is not inflected posteriorly. 
Char, specif—Size about that ofthe wolf. Inferior canine directed 
upwards, its section nearly elliptic; a faint posterior, no anterior 
cutting edge. Fourth premolar rather large, with an anterior 
basal cingulum which is angulate upwards, and is not continued 
on the inner side of the crown. Cusps of the heel each sending a 
ridge forwards, the internal lower, obtuse and descending to base 
of inner side. of large cusp; the external larger, with an acute an- 
terior cutting edge continuous with the cutting edge of the large 
cusp. True molars with an external, but no internal basal cingu- 
lum. Border of heel with one large and three smaller tubercles, 
the former with, the latter without, anterior cutting edge. Ena- 
mel of all the teeth nearly smooth. All the cusps are rather ob- 
tuse. Measurements——Length of inferior molar series: M. .080; 
long diameter of base of canine .013; length of true molar se- 
ries .044; length of base of Prem. iv. .016; elevation of crown of 
a0. .014 ; Jength of base of M. 11..016; width of do. in front .ort, 
elevation of do, .ot4. The measurements of the jaw are not given, 
as the animal is not adult, the last molar not being yet protruded, 
the lower (? Puerco) Eocene beds of New Mexico. 
Deltatherium absaroke sp. nov. Char. specif.— This animal 
repeats very closely the characters of the D. fuxdaminis, but 
is much smaller in all its proportions. Both branches of the 
lower jaw accompany the anterior part of the skull, so that the 
dentition is well displayed. There are three inferior tubercular- 
sectorial molars, as in Styfo/ophus, but the fourth premolar has an 
internal tubercle, which is not found in that genus. The same 
tooth has a rudimental heel. The third inferior premolar is large, 
has a rudimental heel, and no inner lobe; the first premolar is 
two-rooted. There are only three inferior incisors. The supe- 
rior molars are triangular, and the external posterior angle is not 
Produced. The external cusp of the fourth posterior molar is 
compressed and simple, as in Proviverra; in Stypolophus ¢ Proto- 
fomus) viverrinus and S. multicuspis, that tooth has a conic cusp 
and large posterior heel. The two posterior sides of the last 
Superior molar are equal. Canines well developed. Enamel 
smooth, 
Measurements,—Length of superior molar series: M. .0216; of 
Superior true molars .o107. Diameters of second true molars: 
anteroposterior .0033 ; transverse .0055; width of jaws at same 
tooth .022; width between bases of canines .008; depth ramus 
Mandibuli at Prem. 1 .005; at M. 111.009. From the Wasatch 
Eocene of the Big Horn river; J. L. Wortman.—F. D. Cope. 
A Laramie Saurtan IN THE Eocenr.—It is known that in 
North America the saurians of the Laramie formation are mostly 
*See Proceedings American Philosophical Society, July, 1880. 
