Marsh Collection^ Peahody Museum. 23 



type of jEluroiJierium is figured and described, a new species 

 added, and its ancestral relationship to the Felidse discnssed 

 and reaffirmed ; the organization of the Creodonta and their 

 relations to the Metatherian Marsupials are considered, a new 

 classification is proposed, and the families are redefined ; the 

 Yiverravidge and Palseonictidge are removed to the Carnassi- 

 dentia ; the family Mesonychidse is considered, the genera of 

 the Mesonychinse are defined, a new genns, Harpagolestes, is 

 proposed and defined, and the osteology of Dro^nocyon vorax 

 given in full, with numerous illustrations ; the small pelvic 

 outlet may have indicated extreme helplessness of the young at 

 the time of birth, like the Marsupials, and a possible cause for 

 the extinction of the line ; the evolution of the phylum is con- 

 sidered, and the progressive modifications of the teeth and 

 limbs are pointed out ; the origin and homologies of the mam- 

 malian tritubercular molar are fully discussed, and dissent is 

 expressed from the theory of Migration or Rotation of Osborn ; 

 the family Oxysenidse is considered, the arrangement of the 

 genera discussed, and two subfamilies, Oxygeninge and Limno- 

 cyoninge, are proposed and defined ; the genera of the Oxyse- 

 ninee are defined, the type specimen of Patriofelis ferox is 

 figured and described in detail, and the probable habits of the 

 species are rediscussed at length ; the genera of the Limno- 

 cyoninse are defined, one new species is added, and the synon- 

 ymy of the others given ; many new points are added to a 

 knowledge of this group, its possible Insectivorous relation- 

 ship is pointed out, and one species, at least, is thought to have 

 been aquatic in habit ; the family Hyeenodontidse is redefined, 

 and the Bridger species of Sitiopa^ of which two are added, 

 are described in detail ; much of the osteology of Sinopa agilis^ 

 w4th illustrations of skull, fore foot, and limb bones, is given ; 

 the probable origin of the Hygenodonts and Pterodonts is con- 

 sidered, some further observations on the Marsupial or Meta- 

 therian relationship of the Creodonts are made, and their 

 probable origin is considered. 



