20 THE HOESE. 



eries by Wortman of complete skeletons of more 

 than one individual with all their bones in connec- 

 tion that we were put in possession of almost as per- 

 fect a knowledge of its osteological characters as of 

 any animal now existing. The figures and descrip- 

 tions published by Professor Cope,* and the excel- 

 lent casts sent to this country of one of the skeletons, 

 have made this knowledge widely accessible. Al- 

 though this creature was of an extremely generalized 

 form, it was obviously so far separated from the 

 primitive mammalian type, whatever that may have 

 been, as to come within the definition of the ungu- 

 late group, using this term in its widest sense. The 

 terminal bones of the toes were of such a form as to 

 show that they were incased in hoofs, instead of car- 

 rying claws, and it had no clavicles. The teeth also 

 were adapted for a herbivorous or omnivorous diet. 

 Phenacodus, however, does not stand alone, even 

 in our present state of knowledge ; it belongs to a 

 family of which several generic modifications are 

 already described, and remains of still more general- 

 ized forms, the Periptychidce of Cope, are found in 

 the Puerco Eocene beds of New Mexico, probably 

 still older than the Wasatch. Forms apparently 

 allied have also been discovered by Rutimeyer in 



* Report of the United States Survey of the Territories, vol. 

 iii. 1884. 



