CREODONTA. 291 



that of the inner posterior. The posterior tubercular heel is low, and sup- 

 ports an oblique ridge which bounds a deep groove behind the outer cusp, 

 no doubt to receive the molar of the upper jaw. This arrangement is not 

 seen in 8. pungens. The premolar is a flat cone with faint traces of a 

 tubercle behind, and cingulum on inner side. 



Length of crowu molar , 0050 



Height of inner cusp 0040 



Length of heel 0025 



Width of crown 0030 



Height of crown piemolar 0040 



. Length of crown premolar 0040 



Found in the Eocene bad lands of Black's Fork by the writer. 

 Stypolophus pungens Cope. 



Loc. cit., 1872, p. 466; Paleontologlcal Bulletin No. 2, p. 1, August 3, 1872. 



Plate xxiv, fig. 8. 



This is the type of the genus, and is represented by the posterior part 

 of a mandibular ramus which supports the last two molars. 



The species is of medium size in the genus, and has a rather shallow 

 mandibular ramus. The heels of the molars are well developed and have 

 a raised border. The inner cusps are not much elevated, the external one 

 much exceeding them. The masseteric fossa is well defined anteriorly, and 

 a well-marked angle bounds it below. There are no cingula on the molars, 

 and the enamel is smooth. 



The measurements are: 



M. 



Depth of ramus at last molar Oil 



Length of last molar 0072 



Width of last molar, posteriorly 0040 



Height of inner tubercle 0062 



Height of external tubercle, anterior .0040 



This species was about the size of the gray fox. 

 From the bluffs of Cottonwood Creek, Wyoming. 



Stypolophus brevicalcaratus Cope. 



Loo. cit., p. 459; Paleontological Bulletin No. 3, p. 1, August 7, 1872. 

 Plate xxiv, fig. 9. 



Established on a portion of the left mandibular ramus, containing the 

 penultimate and antepenultimate molars, of an animal of larger size than 



