Mammals 29 



some confusion in the application of this name, arising from the 

 fact that Linnaeus included a variety of different animals under 

 it. Warren uses Mustela for the martens, and Putorius for the 

 weasels, but I follow Miller's more recent work and call these 

 genera Martes and Mustela respectively. No less than four 

 kinds of weasels occur in Colorado. The large black-footed 

 ferret (Putorius nigripes), with the feet and band across the face 

 black, stands apart from all the others as the only American 

 representative of the subgenus Putorius in the strict sense. This 

 is the group containing the European polecat, of which the 

 English ferret, used for catching rabbits, is generally supposed to 

 be a domesticated variety. The ferret is generally yellowish- 

 white, whereas the polecat is a dark brown, with the under parts 

 darker than the back. Linnaeus regarded the ferret as a dis- 

 tinct species, calling it Mustela furo, apparently from the "red, 

 fiery eyes."* It was alleged to inhabit Africa, and to have been 

 brought to Europe in a state of domestication. Miller, examining 

 ferret skulls, found that they were not like those of the common 

 polecat, but agreed with the Asiatic species, Mustela eversmanni. 

 This seems to lead to a curious complication, whereby M. furo, 

 being the earlier designation, becomes the nomenclatural type of 

 the species, and the wild animal has to be called M. furo evers- 

 manni. The American ferret or polecat, found in Colorado, is a 

 much paler animal than the European, with the under parts 

 somewhat lighter than the upper, as is usual among mammals. 

 The differences so impressed Trouessart that he made it the type 

 of a distinct subgenus, called Cynomyonax, meaning "king of the 

 prairie dogs." His conception of regal functions was interesting, 

 for it feeds on the prairie dogs, following them into their holes. 



The other Colorado weasels are smaller, and turn white in 

 the winter. The European stoat or ermine is a member of this 

 group, ermine robes being made from the white skins and the 

 black tipped tails. Our smallest species, Mustela streatori leptus 

 of Merriam, first discovered at Silverton, is only nine and one- 

 half inches long. It has also been taken in Larimer, Boulder, 

 Gunnison and Montrose Counties. Mr. Warren writes that he 

 has one from El Paso County. The remaining two are the long- 



*It has also been suggested that the name came from the Latin fur, a thief: but furo 

 f urui, is the Latin verb to rage. 



