1890.] 



NATURAL SCIENCES OF PHILADELPHIA. 



61 



The molars of this genus differ from those of 

 Wjl DissacHs, Cope, in the double ])osterior basal 

 cus])s and from those of Triisodon, Cope, in the 

 r- less distinct separation of the internal cusps 

 (? metaconid). They apparently agree with 

 both the above types in the loss or reduction 

 /'. Hyaenodictis. in- of the antero-internal cusp (paraconid) of the 

 teinal and superior views primitive triangle. There is a small cusp upon 



of the fourth premolar ^, , . , p ,, , , . 



and second molar, xi. ^"^ anterior slope ot the crown but this can 

 hardly represent an element of the primitive triangle. 



TRICUSPIODON, Lemoine. 

 Proposed '85, p. 204-5. See also '88a, p. 2. 



This genus is apparently well established upon the type of a single 

 lower molar, bearing a lofty primitive triangle with the three cusps 

 complete. This portion resembles the tuberculo-secto- 

 rials of Palaeonictis, Stypolophus, Dich/midis, or on a large 

 scale the recent Centetes but the crown as a whole is 

 well distinguished by the rudimentary character of the 

 heel. This consists of a low simple cusp instead of the 

 broad talon seen in the above genera. Dr. Lemoine has 

 rightly recognized this tooth as closely related in form to 

 the molars of the Jurassic Peramus and Spalacotherium. 

 Procyonictis (see '85a, p. 215) is founded upon a single 

 tooth much less characteristic than the above. It is com- 

 posed of a lofty main cone with anterior and posterior 

 It is possibly a premolar of one of the above genera. 



MULTITUBERCULATA. 



NEOPLAGIATJLAX, Lemoine. 



A^. (Plagiaulax) eocaemis, Lem. '80, p. 12; A^. Marshn,"^^!), p. 12 (reprint). 

 Genus established, '82b. N. Copei, '85, p. 213. 



This well-established genus is distinguished from Plagicmlax and 

 Ptilodus by the presence of but one premolar. Dr. Lemoine's col- 

 lection embraces a number of isolated teeth, among them the upper 

 molars. These (c) are composed of three rows of minute cones sep- 



