198 THE WASATCH A>T> BRIDGER FAUN^. 



of Didy'mictis, and throu<rli them to tlie tubercular ^^ectorials of the Oxycc- 

 nidce, with which they agree in essential composition. 



On the other hand, resemblances between the dentition of Esthont/x, 

 and the supposed Lemurine genus Pehjcodus are not wanting, and the 

 rodent-like anterior teeth of the Lemuroid Chiromys suggest still further 

 affinities between the Eocene members of that group and the Tilloclonta. 



There are two genera of this group known to me from the American 



Eocenes, whicli differ as follows: 



Anterior lobe of fourth inferior premolar a cone ; two inferior incisors Conorijctes. 



Anterior lobe of fourth inferior jjremolar with a concave edge; three infe- 

 rior incisors Esthomjx. 



As the scaphoid and the lunar bones are separate in Esthonyx, that 



genus cannot be placed in the Erinaceidce. 



CONORYCTES Cope. 



Paleoutological Bulletin No. 33, p. 486, Sept. 30, 1881; Proceedings Amer. Philos. See. 1881, p. 466. 



Dental formula, I.-; C. ; I'-ui. ' ''; M. '. Incisors small; canines 

 1 \ 4 o 



large, with conic crowns. First two superior and inferior premolars with 



conic crowns; first inferior one-rooted, the second two-rooted, the fourth 



with an anterior conic cusp and a posterior grinding heel. Superior true 



molars transverse, with two external cusps. The inferior consist of two 



lobes, of subcylindric section, separated by deep vertical grooves. Enamel 



developed on internal and external faces of crowns 



CONORYCTES COMMA Cope. 



Loc. Slip. cit. 

 Plate XXIII (1, fiKS. 1-.^; XXV c, tigs. .3-4. 



Founded on a laandiljular ramus which lacks the last molar, and has 

 the crowns of the others worn. The external faces of the molars are much 

 more exposed than the internal, and are somewhat contracted upwards. In 

 the unworn crown there is a distinct anterior inner cusp, which is soon con- 

 founded on attrition. The heel of the last premolar has a crescentic section, 

 the internal horn the narrower. The anterior lobe is a robust cone. The 

 base of the second and tliiiil pirmujar is oblique to the axis of the ramus 



