238 LAND MAMMALS IN THE WESTERN HEMISPHERE 



modern hares, squirrels, beavers, sewellels, pocket-gophers and 

 kangaroo-rats. A few Insectivora of doubtful reference have 

 been found. Among the Carnivora there was also consider- 

 able variety : dogs, large and small, were abundant, but all 

 of them were decidedly primitive from the modern standpoint ; 

 the cats were represented both by the true feUnes, which 

 were probably immigrants, and by the fsabre-tooth series. 

 There were several large and powerful mustelines, or members 

 of the weasel family, which were likewise immigrants, one 

 of which resembles in many ways the lAodern Wolverene 

 (Gulo). Very interesting is the beginning of the raccoon 

 family (Procyonidse) or, at least, what is believed to be such, 

 which arose from a branch of the dogs ; this most ancient of 

 the raccoons was \Phlaocyon, a small and slender animal. 



The earliest traces of the Proboscidea in America have 

 been reported from this formation, but the fragmentary speci- 

 mens are inconclusive. The Perissodactyla are among the 

 commonest fossils. The rhinoceroses belonged to native stocks, 

 including both the horned and hornless forms. The horned 

 genus {^Diceratherium) differed from all other rhinoceroses 

 in having a transverse pair of horns on the nose, and the species 

 of the lower Miocene were quite small and light ; the hornless 

 genus {\Como'pus) was a larger and heavier animal. Tapirs 

 are rare as fossils and consequently not well known. While 

 there were several kinds of horses, they all agreed in having 

 short-crowned and relatively simple grinding teeth and three- 

 toed feet ; they were smaller and of lighter, more slender build 

 than those of the middle Miocene. The wonderful aberrant 

 perissodactyls with clawed feet, the fchalicotheres (suborder 

 fAncylopoda), appear to have been more abundant in the 

 Arikaree than at any other time in North America, though 

 their history in this continent extends from the middle Eocene 

 to the lower Pliocene. ^Mowpus, the lower Miocene genus, 

 was as grotesque a creature as could well be imagined and, in 

 advance of experience, no one ever did imagine such a beast. 



