66 ARCHAEOTHERIUM. 
Archaeotherium (Zniclodon?) robustum, Lerpy. 
(Prate X., Figs. 8-13.) 
Arctodon, Leidy: Proc. Acad. Nat. Sci., 1851, v. 278. 
Archaeotherium robustum, Leidy: Owen’s Rep. of a Geol. Surv. of Wisce., ete., 572. 
This species is proposed upon fragments of the crowns of the posterior two 
molars of the left side, and a portion of the crown of a canine tooth probably of 
the left side inferiorly. 
These specimens, which belong to the collection obtained by Mr. T. A. Culbert- 
son, I at first supposed indicated the existence of a genus allied to the Bear; but 
by comparison, they have since been determined to belong to a species of Archaco- 
therium larger than that described in the preceding pages. 
The fragments of molars (X. 10-13) are almost identical in their form with 
the corresponding portion of the same teeth of Archaeotherium Mortoni, except that 
in the last molar the posterior basal ridge rises into a conical eminence or fifth 
lobe, which is more regular, but less prominent, and more expanded at the base than 
those in advance. The teeth have been almost a fourth larger than those corre- 
sponding of Archaeotherium Mortoni. 
The fragment of the crown of a canine (8, 9) resembles more that of the Bear 
than that of any existing ungulates. It is curved conical in form, and presents a 
slight longitudinal ridge defining its outer and inner faces. It is completely covered 
with enamel, which is thinnest at the inner face, and is unworn in the specimen. 
