I 2 Bulletin American Museum of Natural History. [Vol. XI V, 



III— Family ARCTOCYONID^ {Gervais) Cope. 

 The Manus and Fes of Clceitodon. 



In a previous article ('97, p. 289) I have given some account of 

 the foot structure of this interesting Creodont, now more fully 

 known than when first described by Cope ('83, p. 547). This 

 description can now be supplemented by figures of the fore and 

 hind feet. 



It was mainly on the characters of Clcenodon {Mioclce?ius) 

 ferox that Professor Cope based his views as to the position of 

 the genus Mioclcenus Cope ('84, p. 324), referring it to the Arcto- 

 cyonidse, which included this and many other species of diver- 

 gent affinities, separated by Scott ('92) as distinct genera. 

 Judging from Cope's descriptions of the skeletal material of M. 

 ferox at his command, he was evidently strongly impressed with 

 its resemblance to Marsupials, an idea which led him astray in 

 parts of his description. I do not think that this resemblance is 

 wholly a case of parallelism, for all the Creodonta of the Basal 

 Eocene were quite nearly allied, and certain of them show 

 primitive marsupial characters that it is very difficult to explain 

 without admitting a closer connection between Marsupials and 

 Placentals than their modern differentiation would lead one to 

 believe. Clcenodon has, however, no marsupial characters except 

 such as must be considered an inheritance from the common 

 stock which gave rise to both Marsupials and Placentals. Its 

 progressive characters are placental carnivore. 



Several genera of this group have been described. Without 

 discussing the validity of Hyodectes and Heterobortcs, defined by 

 Cope on the basis of descriptions of European Arctocyons, we 

 may say that three genera are sufficiently known for discussion of 

 their relationships. These are : 



Arctocyon Blv., type A. primavus Blv.; referred species, A. ger- 

 vaisi, A. deulii Lem., all Basal Eocene of Europe. 



Anacodon Cope, type A. ursidens Cope, Lower Eocene of 

 America. 



Clcenodon Scott, type C. {MioclcBnus) ferox Cope ; referred 

 species, C. corrugatus (Cope), Basal Eocene of America. 



To these should perhaps be added Arctocyonides Lem., type A. 

 sp. innom. Lem., Basal Eocene of Europe ; referred species ? 



