250 O. C. Marsh—Notice of New Tertiary Mammals. 
is also proportionally broader than the corresponding teeth of 
the present species, and hence the two must be regarded as 
distinct. 
Measurements. 
Space occupied by four upper premolars, ---------------- 61: 2 
Extent of three upper true molars, .........--......---.46" | 
Antero-posterior diameter of first upper premolar, --- - --- 13° 
Antero-posterior diameter of second upper premolar, ----- 19° 
‘Transverse diameter, ............-.- fa mls Oe PS oe ee 18° 
Antero-posterior diameter of last upper molar, ----.------ 14° 
Werbe dinmetet, 62 oo co caress eee ee 19°5 
diets of aleeneni oo a ee 68° 
Lengel of witeipatns, 6ic5 222 2-2 -32 
Antero-posterior diameter of tibia at distal end, _..-- - -26° 
Avahiverse ditmeter,.. 2572 es a Ae 33° 
All the known remains of this species are from the Miocene 
of Oregon. They indicate an animal somewhat exceeding a 
sheep in size, and with longer limbs. 
the following particulars: the skull is depressed between the 
orbits; the molar teeth extend farther back below the orbit; 
the external cusps of the upper molars have their buttresses 
much stouter, and the concavities between them divided by 
more prominent vertical ridges. 
Measurements. ott 
Space occupied by four upper premolars, -_--.---------- hte 
Antero-posterior diameter of first upper premolar, -- - - --- 9 
Antero-posterior diameter of second upper premolar, - - - -- 13° 
ae a a a : 
Antero-posterior of last upper premolar, __.------------- 13° 
Tinaniens diameter, ahs . : --15°5 
Antero-posterior diameter of last lower molar, ---- ------ 17" 
NIN CM a a 
Extent of upper molar series (second specimen), ---- ----- 82° 
Extent of three upper true molars,..._. __......-------- 37° 
lj remains of this species indicate an animal about as large 
a 
* ue specimens on which the above description 1s 
