Cope] J-O^ [Dec. 16, 



Char, specif. Broken mandibular rami of two individuals constitute 

 the basis of my knowledge of this species. It is of the size of the Phena- 

 codus primcevus. The last inferior molar is wedge-shaped with the very- 

 obtuse apex posterior. It displays two slight transverse elevations anterior- 

 ly which represent the usual cusps. Grinding surface generally nearly 

 flat. The posterior half of the crown of the penultimate molar is flat, and 

 is separated from the anterior half by a transverse groove. Its surface is 

 marked by shallow branching grooves. 



The molar preceding this one in the broken specimen is probably the 



first. It is possible from its slightly worn condition that it is the fourth 



premolar, but the form is that of a true molar. The surface of the crown 



is marked by shallow grooves not very closely placed. The three premolar 



teeth in advance of this tooth are broken off. Their bases are narrow. 



There are no basal ciagula on the molars. 



Measurements. M. 



Length of posterior true molars 033 



- . „ _, TTT r anteroposterior 015 



Diameters of M. Ill { . Mn 



I transverse 010 



_. „„ „ T r anteroposterior.. .' 015 



Diameters of M. ? I ^ . „^ 



( transverse 011 



Depth of ramus at M. II 030 



The characters of the teeth of this species are something like that of 



some of the Palaioclmri of the Miocene, and resemble more those seen in 



some of the bears. 



Oligotomus osbornianus, sp. nov. 



Char. gen. Dental formula ; I. ?, C. ?, P-m. ? £ ; M. f . External faces 

 of external lobes of superior molars separated by a ridge ; anterior ex- 

 ternal cusp of cingulum little developed. Premolars of superior series 

 different from true molars, Avith only one internal lobe. Fourth inferior 

 premolar similar to the true molars. Cusps of inferior molars connected 

 by diagonal ridges, forming Vs. A diastema in front of the second pre- 

 molar. 



This genus is a good deal like Lambdotherium, so far as known. Its 

 superior molars are much like those of Aeoessus, and their intermediate 

 and internal tubercles are those of Hyracotherium. 



The two or three species known to me are of small size. 



Char. spec. The true molars of both maxillary bones, with the fourth 

 premolar of one side are preserved more or less perfectly, with four in- 

 ferior molars on two fragments of the lower jaw. 



The external tubercles of the superior molars are nearly erect, and have 

 a lenticular section. The rib which separates their external faces is 

 prominent, and terminates in a free apex. The base of each face is marked 

 by a strong cingulum, but the posterior one is very short. There is a strong 

 anterior basal cingulum, but no posterior or internal one. The anterior 

 inner tubercle is larger than the posterior. The intermediate tubercles are 



