524 



LAND MAMMALS IN THE WESTERN HEMISPHERE 



the phyla into which the family was divided became blended 

 in a common stock at that stage. 



A second phylum, now entirely extinct, is that of the fbear- 

 dogs, which is not certainly recorded later than the middle 



^^^,,,^>5::::r:N^ Pliocene, though 



\^""^V^ /^i^^VlS/fe) some have been 



^ — J (^ (^) w \^^^(^ doubtfully reported 



@ from the older Pleis- 



FiG. 257.— Upper teeth of iDaphcenus felitius. tOCeue of the Great 



p. 4 = fourth premolar. (After Hatcher.) -r»i • i , i 



Plains and the re- 

 markable Californian genus, ^Hycenognathus, may have been 

 an offshoot of the same stock. The phylum was characterized 

 by the unusually large size of the molars and by certain other 

 features, which, however, are not 

 known to have persisted through 

 the entire series from first to last. 

 In the middle Pliocene lived some 

 very large bear-dogs, of the genus 

 ^Borophagus, the teeth of which had 

 a strong likeness to those of the 

 hyenas and probably the animals 

 had hyena-like habits, feeding largely 

 upon carrion and crushing the stout- 

 est bones with their massive teeth. 

 The same, or a very similar, genus 

 lived in the lower Pliocene, but none 

 of the species of that date is at all 

 well known. In the upper Miocene Fig. 258.— Right manus of Wa- 



. . . I'll phcenusfelinus. Sl.,scB,ph.o-\\ina.T. 



occurred several species which have p^.. pyramidal. Ps., pisiform. 

 been referred to the European ^- unciform. (After Hatcher.) 



1 1 r-v • Compare with Fig. 32. p. 82. 



genera, jAmphicyon and jDmocyon. 



The latter was an enormous canid, equalling in size the largest 

 of living bears, the great Kadiak Bear of Alaska, and, though 

 probably having a long and heavy tail, was much like a bear 

 in appearance. The teeth indicate a more exclusively car- 



