BUNOTHERIA. 737 



M. 

 Length of head 008 



„. ^ . , f .(vertical 009 



Diameters naviciilaT facet { „,„ 



( transverse "l* 



Width of cuboid facet 007 



The Puerco beds of Northwest New Mexico. Discovered by D. 



Baldwin. 



PTILODUS Cope. 



Supra page 172. 



A second species of this genus must be here recorded. 

 Ptilodus trovessartianus Cope. 



American Naturalist, 1882, p. 686. 

 Pl.ate XXV f, fig. 19. 



This species is represented by three of the characteristic fourth inferior 

 premolars, one of which stands on a part of the ramu.s, giving its depth. 

 These differ from those of the P. medicevus in their uniformly smaller size, 

 and in their strongly serrate posterior edge. The number of lateral ridges 

 is twelve, as in P. medicevus. Length of fourth premolar, M. .0055; eleva- 

 tion of do. .0040; depth of ramus at Pm. iv, .0057. Discovered by D. 

 Baldwin, in the Puerco beds of New Mexico. Dedicated to the dis- 

 tinguished mammalogist Dr. E. L. Trouessart, of Angers. 



BUNOTHERIA. 

 The name Bunotheria was proposed by me for a series of Mammalia 

 which resemble in most technical characters the Edentata and the Rodentia. 

 That is, they agree with these orders in having small, nearly smooth cere- 

 bral hemispheres, which leave the olfactory lobes and cerebellum entirely 

 exposed, and in some instances the hemispheres do not cover the mesence- 

 phalum also. From the two orders in question, however, they are easily 

 ^ distinguished. Their enamel-covered teeth separate them from the Eden- 

 tata, while the articulation of the lower jaw is different from that found in 

 the Rodentia. It is a transverse ginglymus, with a postglenoid process in 

 the Bunotheria, as distinguished from the longitudinal groove, permitting 

 anteroposterior motion, of the Rodentia. 



Such a group as is thus characterized will include two existing groups 

 47 o 



