O. 61 Marsh — Notice of New Fossil Mammals. 329 



presence of two upper incisors on each side. The superior- 

 dentition is as follows : 



Incisors, 2 ; canine, 1 ; premolars, 4 ; molars. 3. 



In figure 9, below, is shown the type specimen, which is 

 evidently the skull of a large adult male. Figure 10 repre- 

 sents a female skull apparently of the same species. The 

 latter skull is much less robust, and the horn-cores are very 

 small, although the dentition and sutures show that the animal 

 was fully grown. 



Fig. 9. 



. 



SS : 



Fig. 10. 



Figurk 9. — Skull of Menops varians. Marsh ; front view (male). 

 Figure 10. — Skull of same species; side view (female). 

 Both figures are one-eighth natural size. 



The interesting specimen shown in figure 9 was obtained by 

 Mr. George A. Clarke, from the Brontotherium beds of Dakota. 

 The other specimen was found in the same region by Mr. J. B. 

 Hatcher. 



21a 



