52 



CARNIVORA 



ORDER III 



-ctst. 



Hapalodedes Matthew. Teeth somewhat compressed. Molars without 

 metaconid. Wasatch and Wind River beds. Basal Eocene. 



Pachyaena Cope. Dentition ' ' ' ' . Limb bones stout, ungual phalanges 



hoof-like, angle of lower jaw sometimes inflected. This form attained the size 

 of a bear. Wasatch beds of New Mexico and Wyoming. Middle Eocene ; 



Paris Basin. 

 .;f^.._ Harpagolestes Wortman. 



d'anium broad and short. 

 M^ wanting. Humerus lack- 

 ing entepicondylar foramen. 

 H. immanis Matthew, about 

 the size of a bear. H. (Mes- 

 onyx) iiinteiisis Scott. Uinta 

 Beds. 



Sytioplotherium Cope (Dro- 

 mocyonMa,Ysh). Cranium and 

 limbs somewhat elongated ; 

 manus and pes tetradactyl, 

 astragalus with deeply 

 grooved trochlea. S. lanius 

 Cope. S. vorax Marsh sp. 

 Bridger beds. 



Mesonyx Cope (Figs. 77a, 

 78). ]\'P lacking. Humerus 

 without entepicondylar 

 foramen ; lachrymal bone 

 prominent. M. immanis 

 Wortman. M. oMusidens 

 Cope. Bridger beds. 



The skeletons of Mesonyx 

 and Dromocyon are very satisfactorily known. The claws are thick and cleft 

 at the tips, the metapodials closely appressed as in the Canidae. 



Fig. 78. 



Mesonyx obtiisidens Cope. Bridger beds of Middle Eocene ; Wyoinin 

 A, Inferior aspect of skull. B, Pes. Vs- (After Matthew.) 



Tribe 2. PSEUDOCBEODI. 



M ^ or M I functioning as carnassials. Claws cleft, mamis and pes mesaxonic. 

 Fibula articidating with calcaneum. Zygapophyscs of lumbar vertebrae cylindrical 

 or inrolled. 



Family 3. Oxyaenidae. 



P^ with inner cusp. M^ placed transversely, i/^ usually larger than My 

 Cranium of moderate size, with broad basis cranii : mandible massive with strong 

 symphysis. Extremities plantigrade, pentadactyl, claws more or less fissured at the 

 tips, blunt; toes spreading in aquatic forms. 



Osborn regards the genus Palaeonictis as ancestral to the Felidae, and 

 according to Wortman Patriofelis stands in similar relation to the Pinnipedia. 

 The researches of Matthew fail to indicate that either genus gave rise to 

 later forms. 



