Cope.] 396 (April 15, 
I. Internal cones of superior molars separate from external lobes. 
A. Cusps of inferior molars not completely united ; 
a, External lobes of superior molars more or less conic. 
Inferior premolars III and IV compressed, three lobed; a diastema both 
behind and before P-m. II...........-...ee00: what Rhagatherium. 
AA, Cusps of inferior molars united into two Vs. 
a. Incisors present. 
&. No diastema in front of second inferior premolar. 
Second premolar without inner lobe; last molar with one inner cone..... 
Leurocephatus. 
Second premolar with inner cone; last superior molar with an inner 
CONC s 2s ai08 wie table nba tars sofewae 6 «easy sevbbens ieyemeds ots Palewosyops. 
Second premolar with inner cone; last superior molar with two inner 
(CONES 35s fo5.5 aa. ca eee A Deo A RR Nea Raed ea OD DSli Limnohyus. 
£8, Adiastema in front ofsecond inferior premolar. : 
Two inner cones of last superior molar...............005 Lambdotherium. 
aa, incisors absent from both jaws. 
Last superior molar with one internal cone............... Nestoritherium. 
II. One or both internal cusps of superior molars united with the exter- 
nal lobes by cross-crests. : 
a, External cusps of superior molars more or less conic ; 
An anteroexternal cingular CUSP...... esse cere eee eee Propaleothertum. 
aa. External lobes of superior molars, inflected Vs. 
B. No crescentic inner lobes. 
No intermediate lobes...............4. Wy ataia casi dak tareiate Ohalicotherium. 
ff. One or more lobes of each molar crescentic. 
Intermediate lobes, and one internal cone of superior molars...........- ox 
Meniscotherium. 
The following regions have thus far furnished species of the above-men- 
tioned genera: 
Europe—Rhagatherium, Propaleotherium, Chalicotherium. 
N. America—Leurocephalus, Paleosyops, Limnohyus, Lambdotherium, 
Meniscotherium. 
Asia—Westoritherium. 
Of the American genera, Leurocephalus 8. S. & O. has been found by 
the Princeton exploring expedition of 1877 in the Bridger formation, but I 
have not met with it myself. Meniscotherium Copa, is known from a 
single species found by myself in the Wasatch formation of New Mexico, 
and described in my report to Capt. G. M. Wheeler (1877). 
