PLATE XXVII 



Described 

 on Page 



Ctenacodon scindens Simpson. 20 



Fig. I. Left lower jaw with P2.4 and M^, external view. X 10 diam. 

 A.M.N. H. No. 28063. Photograph from the American Museum of 

 Natural History. 



Paurodon valens Marsh. 49 



Fig. 2. Left lower jaw with C, Pi-g, and M1.4, external view. X 3 diam. 

 Type. U.S.N.M. No. 2143. Photograph from the United States Na- 

 tional Museum. 



Archaeotrigon brevimaxillus Simpson. 5^ 



Fig. 4. Right lower jaw with C, P1.2, and M1.2, internal view. X 3 diam. 

 Type. U.S.N.M. No. 2793. Photograph from the United States Na- 

 tional Museum. 



Fig. 5. Same, crown view. X 3 diam. Photograph from the United States 

 National Museum. 



Amblotherium gracilis Marsh 66 



Fig. 6. Left lower jaw with P4 and Mi.g, external view. X 3 diam. U.S. 

 N.M. No. 2693. Photograph from the United States National Mu- 

 seum. 



Fig. 7. Same, crown view. X 3 diam. Photograph from the United States 

 National Museum. 



Fig. 8. Left lower jaw with P3.4 and M1.7, internal view, X 3 diam. 

 (Type of Laodoti venustus.) U.S.N.M. No. 2142. Photograph from 

 the United States National Museum. 



224 



