612 OREODONTA. CARNIVORA. 



separation of the scaphoid and lunar bones of the carpus. 

 They also approximate closely to the Condylarthra, and show 

 some resemblance to the Insectivora, and to the carnivorous 

 Marsupials (through the Sparassodontidae, p. 540), but they 

 differ from the latter in having a complete succession of 

 teeth, and in being without the inflected angle of the lower 

 and the palatal vacuities characteristic of that group. It is 

 clear, therefore, that like the Condylarthra they are a central 

 group with affinities in several directions, and that it is safest 

 in the present state of knowledge to accord them independent 



ordinal rank. 



In addition to the important characters ah-eady referred to, the following 

 may be mentioned. The skull is carnivora-like and the muzzle usually 

 elongated. The dentition is normal, ifcip|mfor slightly reduced. 

 The canines are powerful and sometimes two-rooted. The back-teeth are 

 incUned to be trenchant, but the carnassial modification, so characteristic 

 of Carnivora, is not found. Tlie ulna and radius are separate, the carpus 

 has a centrale and the scaphoid and lunar are not united. The terminal 

 phalanges are often spHt and flattened at the ends. The lumbar region of 

 the vertebral column is rigid owing to the form of the zygapophyses. 

 They appear to have been, in some cases at least, semiaquatic. The prin- 

 cipal genera are : Arctocyon Blv., a bear-like omnivorous form ; Mesonyx 

 Cope, a thylacine-like form ; Proviverra Uut. ; Sinopa heidy (Sty polophus) ; 

 PatriofeUs Leidy, a seal-like form ; Miacis Cope ; and Hyaenodon Luizer 

 and Parieu, the most specialised and best known of the group. 



Order 16. CARNIVORA * (FISSIPEDIA). 



Carnivorous, sometimes omnivorous mammals with large 

 projecting canine teeth, almost invariably three incisors on each 

 side in each jaw, cutting premolars, and tuber culate molars. 

 The last upper premolar and the first lower molar are always 

 modified as carnassial teeth. The clavicles are absent or 

 reduced, the scaphoid and lunar bones are fused, the limbs have 

 never fewer than four digits and are unguiculate. The placenta- 

 tion is zonary. 



The Carnivora are by no means all exclusively carnivorous ; 

 a considerable number are omnivorous and some chiefly 



* Gray, Cam., Pachyderm., and Edentate Mamm., Brit. Mus. Cat. 

 1869. C. Grev6, Die geograph. Distrib. de jetzt lebenden Raubthiere, 

 Nov. Act. k. Leop-Carol Deutsch. Alcad. Naturf. zu Halle, 63, 1893. Lydek- 

 ker, Carnivora (Felidae and Viverridae) in Allen's Library, 1895. H. 

 Winge, Jordfunde (Carnivora) fra Brasilien, cum appendice de class, 

 etc.. E Museo Lnndii, 1895. See also Cope, Amer. Nat. 1880, p. 833, 

 and 1883, p. 235. Flower, P.Z.S., 1869, p. 6. Mivart, P.Z.S., 1882, 

 1885. 



