164 Bulletin American Museum of Natural History. [Vol. X.] 



Comparison with Euprotogonia. — Continued. 



Euprotogonia. 



[Torrejon]. 



(g) Tibial spines sharp and prominent ; 

 cnemial crest very prominent and 

 elongate, (f.) 



(10) No fibulo-calcaneal facet. 



(11) Astragalo-cuboidal facet depressed. 



(12) An astragalar foramen ; tibial troch- 



lea in front of foramen, i.e., sub- 

 digitigrade. (f.) 



(13) Meso-cuneiform very short. (('. ) 



(14) Lateral digital reduction advanced: 



ratio of Mts.V : Mts.III : 23 mm. 

 37 mm., or as 2 : 3. 



(15) Metatarsals and phalanges slightly 



curved. (C.) 



Phenacodus. 



Wasatch. 



The same. Cnemial crest 

 prominent, anil shorter. 



less 



The same. 

 The same. 

 No astragalar foramen. Tibial 



trochlea extended further back, 



i.e.. fully digitigrade. 

 The same. 

 Lateral digital reduction still more 



advanced : ratio of Mts.V : Mts. 



Ill : 35 mm. : 73 mm., oras i : 2, 

 The same nearly straight. 



This strengthens the observation of Matthew,' in his recent 

 comparison of these types, that the features in which P/ienacodus 

 differs from Euprotogonia are progressions from the Creodont 

 type, as indicated in the above cohimn by the letter C. 



A far larger proportion of Creodont characters are, however, 

 found in the Amblypod contemporary of Euprotogonia, namely, 

 Pantolauibda, which will be fully described by the writer in a forth- 

 coming paper. 



'Revision of the Puerco Fauna,' Bull. Am. Mus Nat. Hist., Vol. IX, 1897, pp. 305-308. 



