472 Annals of the Carnegie Museum. 



No. 705. Ramus of mandible with molar and premolar teeth. 

 Type of PalcBomeryx americanus Douglass. 



No. 706. Last two upper premolars and greater portions of molars. 

 Provisionally referred in the original description to Palceomeryx 

 americanus Douglass. The reference of this to Dromovieryx is 

 more doubtful than that of the other specimens: 



No. 755. The greater portions of the lower molars in fragment of 

 mandible. Type of Pahzoineryx viadisouiiis. 



No. 2146. A third upper premolar. Referred in the original de- 

 scription to Palceojiieryx ai/ief ica/nis Douglass. 



These specimens indicate animals very much smaller than Dro?no- 

 meryx borealis. 



Dromomeryx ? amei'icanus (Douglass) . 

 (Plate LXII, Figures i and 2 ; Plate LXIII, Figure 2.) 



PalcTomoyx americanus Douglass. " The Miocene Lake Beds of 

 Western Montana," etc., University of Montana, 1899, Pages 20-23. 

 Plate IV, Fig. 3. 



The type of this species is the left ramus of a mandible (No. 705, 

 Carn. Mus. Cat. Vert. Foss.) with the molars and premolars complete. 

 The associated specimen consists of the last two premolars and the 

 greater portions of the molars of the upper jaw (No. 706, Carn. Mus. 

 Cat. Vert. Foss.). This specimen was associated with the type on 

 account of its close similarity in size. The measurements of the teeth 

 approximate those of Dromonieiyx antilopinus Scott. 



The ramus of the mandible is slender, nearly uniform in depth under 

 the raolar-premolar series, and curved downward as in Dromomeryx 

 borealis. Y^ is low and not large. From its principal cusp a sharp 

 ridge extends downward and forward to the anterior portion of the 

 tooth, where it curves inward. A similar but much longer and heavier 

 ridge extends downward and backward from the principal cusp, send- 

 ing a lobe inward about half way between the cusp and the posterior 

 border of the tooth. Pg is much higher, longer, and broader, and 

 there are two inwardly directed lobes before and two behind the 

 principal cusp. The lobe which projects inward from the protoconid 

 is directed backward. On P^^ this element is much larger and forms 

 a subcylindrical cusp opposite the protoconid. My and M2- have 

 large median outer pillars attached to the anterior outer walls of the pos- 



