208 O. C. Marsh—New Tertiary Mammals. 
Measurements. 
Antero-posterior diameter of last upper molar,.........-- sas 
‘ram eres cintietir, ..... os oe ec wee sen sc eee 10°2 
Distance between summits of external pair of cones,...... 4 
Distance between summits of anterior pair of cones,...... 53 
The known remains of this species were found by Mr. H. D. 
Ziegler and Mr. G. G. Lobdell, Jr., last summer, at Grizzly 
Buttes, near Fort Bridger, Wyoming. 
Thinotherium validum, gen. et. sp. nov. 
Measurements. 
Antero-posterior diameter of last lower molar,.......-.+-- 1 
nsverse diameter in front... 000. J0.decseels cu ees : 
Transverse diameter through central pair of cones,.....-- 
Distance between summits of central cones,......-.-+-+> 31 
Antero-posterior diameter of first lower true molar,.....- 8-4 
Passalacodon litoralis, gen. et sp. nov. 
Several small mammals, evidently insectivores, about the size 
of the European hedge-hog, were among the interesting discov 
