5:<^":x 



PANTODONTA. 52A-SV 



is a conic tubercle closely joined Avith the posterior V, and well separated 

 from the anterior first cingular lobe. The basal cingula are well devel- 

 oped, but do not meet on the inner base of the crown. The first or supe- 

 rior cingula meet as usual in an interior angle, but there is a contraction of 

 the anterior crest just before reaching this angle. The first true molar is 

 smaller than the second and has the same general structure. Here, how- 

 ever, the anterior first cingulum is more prominent near the internal angle 

 than the posterior. The charactei's of the premolars do not differ from the 

 corresponding ones of species of Corypliodon. The enamel is delicately 

 wrinkled. The first superior premolar is not preserved. 



Measurements. 



M. 



I anteroposterior 034 



Diameters of crowu of M. iii < transverse 043 



( vertical 015 



I anteroposterior 028 



Diameters M. i < transverse 033 



( vertical. 012 



Diameters Pm. iii ^ »°*'"^°P''«t''"'^^ ^ 



( transverse 030 



It is probable that this species was about the size of an ox. 



CORYPHODON Owen. 



History British Fossil Mammals, 184C, p. 299, tig. 103, 104. Brou Lethiea Geognostica, 1856, p. 842. 

 Hubert, Auuales des Sciences Naturalles, 1856, p. 87. Cope, Synopsis Extinct Vertebrata Eocene 

 of New Mexico, 1875, p. 28. Marsh Amer. Journ. Sei., 1877, 81. Cope, Report U. S. Geol. and 

 Geog. Expl. Survs. W. 100th Meridian, iv, pt. ii, p. 187, part 1877. Proceed. Aiuer. Philos. Soc, 

 1881, p. 166. 



Dental formula: I. -; C. ; P-m. -; 

 3 1 4 



M. -. Canines large, no diastema. 

 3 



Superior j)remolars different from the molars, consisting of an external and 

 an internal V, the external the larger. The first and second superior true 

 molars have two external Vs, the posterior well developed, and the anterior 

 represented by a subconic cusp; a single internal cusp with V-shaped 

 section, the anterior branch extending as a high transverse crest to the 

 external border of the crown, forming the anterior triturating surface. 

 The third true molar differs from the others in having the external Vs 

 united into a crest, which is placed transversely, forming the posterior 



