List of Casts, Models, and Photographs, 



n 



and figures in all textbooks of geology and palaeontology, 

 Phenacodus is the type of the Condylarthra, a very archaic 

 order of ungulates retaining the primitive form of wrist and 

 ankle articulations, five toes on each foot, and pig-like teeth, 

 and considered to represent very nearly the central prot- 

 ungulate type from which all hoofed animals are descended. 

 The size of P. primcevus was somewhat less than that of a pig. 



Price, $10. 



Cope, E. D., Tertiary Vertebrata, Rep. U. S. G. S. Terrs., Vol. Ill, 



B'k I, p. 435, and plates. 

 OsBORN, H. F., Remounted Skeleton of PJicnacodus, Bull. Am. Mus. 



Nat. Hist., X, 1898, pp. 159-164. 



36. Euprotogonia puercensis {Cope) . 

 Hind Foot. 



Torrejon Formation, Basal Eocene, New Mexico. 



Euprotogonia was the ancestor of Phenacodus, and has a still 

 more primitive type of foot. The live toes are tipped with 

 narrow, claw-like hoofs, and in other characters this foot is 



Fig. 5. Eiifootogonia fiiierccnsis. 

 Hind foot. One-half n.itur.il size. 



intermediate between the hoofed animals (Ungulata) and 

 clawed animals (Unguiculata), and indicates the derivation 



