
606 The American Naturalist. [July, 

vie . 11.—Chirox plicatus Cope, 3-2. a, palate with three peer and two molars, iz 
Site 7 by external view, right side. 
B.—TRITUBERCULATE Forms. 
17. Dryolestes tenax (no figure). The type is a lower jaw with 
a mylohyoid groove, in which the number and character of the 
teeth “cannot be determined.” The author’s reference is pro- 
visional. 
18. Didelphops (Didelphodon) vorax (P1. 1v., Figs. 1-3). The 
type is an upper molar, distinguished from Didelphys by interme- 
diate tubercles—This character does not separate it from the large 
number of Trituberculates with similar molars ; the genus is, there- 
fore, undefined at present. The other species, D. ferox and D. 
comptus, are also undefinable. 
19. Pediomys elegans (Pl. 1v., Figs. 23-25). The type is an 
upper molar.—It is not distinguished generically from Didel- 
phodon. 
20. Cimolestes curtus and incisus (PI. 1v., Figs. 8—1 8). The types 
are lower molars——Like Didelphodon, these forms cannot be 
defined ; they are tuberculo-sectorial. 
It is evident that we have here remains of two distinct and 
probably new genera, which may be accepted without definition. 
C-—INCERT# SEDIS. 
21. Stagodon nitor (PI. vii., Figs. 22-25). The types are a few 
teeth with single fangs, referred toa new family, the ‘agai 

