CREODOXTA 611 



Cope, so that, as it can hardly be supposed that we have 

 found remains showing all the variations of structure charac- 

 teristic of this order, it seems not unreasonable to conclude 

 that the Condylarthra constituted a group combining charac- 

 ters now belonging to many mammalian groups and totally 

 unlike any order now existing. If this view conveys a correct 

 appreciation of the facts, it would seem unwise to pick out 

 those of its features which show a faint resemblance to the 

 Ungulata, and allow them to fix the position of the group in 

 the system. We have therefore ventured to confer upon 

 the Condylarthra ordinal rank. 



Periptychus Cope, basal beds (Puerco Formation) of the Eocene of New 

 Mexico, tarsal bones interlock. Euprotogonia Cope, L. Eocene of Xew 

 Mexico, with interlocking carpalia, the tarsus appears to be serial. Mio- 

 claenus Cope, L. Eocene of Xew Mexico, Protoselene Matthew, L. Eocene, 

 X. Mexico. Meniscotherium Cops, L. Eocene of Mexico, carpus and 

 tarsus serial. Hyracops Marsh, upper molars quadritubercular with 

 W-shaped outer wall, and two ridge-like intermediate tubercles. Pleuras- 

 pidotherium Lemoine, L. Eocene, France. Phenacodus Cope, of which 

 complete skeletons have been obtained from the Wasatch Formation of 

 X. America ; digitigrade with 15 dorsal vertebrae ; upper molars with 

 four principal and two intermediate tubercles ; the two anterior premolars 

 with one cusp, the two posterior with main cusp and one or two inner 

 cusps. 



The Astrapotheridae may provisionally he placed here. They are 

 extinct forms from the Cretaceous and Eocene of Patagonia. 



Order 15. CREODONTA.* 



Extinct, digitigrade or semiplantigrade, carnivorous animals 

 with penta- or tetra-dactyle, clawed limbs. The canines are 

 large, the dentition complete and the brain small and weakly 

 furrowed. The carpus has a centrale, the femur a third tro- 

 chanter, and the humerus usually an entepicondylar foramen. 

 Eocene to the L. Miocene of Europe and North America. 



The Creodonta are frequently placed as a suborder of the 

 Carnivora to which they present many resemblances, especially 

 in the dentition ; but they differ from them in the small size 

 of the brain, the absence of carnassial teeth, and in the 



* Cope, The Creodonta, Amer. Nat., 1885. Schlosser, Die Affen, Le- 

 muren, Chiropteren, Insectivoren, Marsupialier, Creodonten und Carni- 

 vorcn des Europ. Tertiars, Beitr. zur Palaeont. Oesterr-Ung., 6, 1887, and 

 9, 1889. Osborn and Earle, Bull. Amer. Mus. Nat. Hist., 7, 1895. Scott, 

 Revision of the X. Amer. Creodonta, Proc. Acad. Nat. Sc. Philadelphia, 

 1892. Wortman, Studies of Eocene Mammalia, 1-4, American Journal 

 of Science, 13 and 14, 1902. 



