HISTORY OF THE CARNIVOKA 551 



So far as North America is concerned, it is scarcely practi- 

 cable to do more than catalogue the genera of the successive 

 geological epochs. Pleistocene musteUnes were very modern 

 in character, differing Uttle from those now inhabiting the con- 

 tinent, though in some cases with different ranges, according 

 to climatic fluctuations. Badgers, martens, skunks and others 

 occurred then very much as they do now and the Boreal Wol- 

 verene extended down to Pennsylvania. Little is known of 

 Pliocene mustelines, the Blanco having yielded fragments 

 of only one genus of uncertain affinities and though several 

 genera occurred in the lower Pliocene, but one, a marten 

 (Martes), can be identified. Unquestionably, North America 

 had many more Pliocene members of the family, but the con- 

 ditions of preservation were unfavourable. 



Much the same is true of the Miocene stages. In the upper 

 Miocene there were a marten (Martes), a weasel (Mustela) 

 and two otters {^Potamotherium and the modem Lutra), of 

 which the marten and the more primitive otter went back to 

 the middle Miocene. In the lower Miocene were several 

 mustelines quite different from any now existing. One of 

 those, \Megalictis, was truly gigantic, with a skull nearly as 

 large as that of a Black Bear and having heavy, pointed claws. 

 This and a similar genus, ]jElwocyon, were related to the Ratel 

 {Mellivora) of India and Africa and, more closely, to the 

 Wolverene. \Oligobunis, a much smaller animal, was ap- 

 parently of the same group. This genus was also in the upper 

 Oligocene, but there represented by a larger species, which 

 was as large as a badger. 



The White River beds have yielded but a single genus, 

 ^Bunodurus, which was the most primitive of American 

 mustelines and had four premolars and two molars in each 

 jaw, though the second upper molar was extremely small. 

 The face was much less shortened than in the modern weasels 

 and the tympanic bullae were short and strongly inflated and 

 had no tubular entrance, and were thus canine rather than 



