78 Miller Synopsis of the Voles of the Genus Phenacomys. 



one hundred well-prepared skins available for examination.* 

 This material shows that, of the nine described forms, the fol 

 lowin six are valid : 



Name. T!II>*' locality. 



1\ htfeniH'iHiis Merriam I ............ Kamloops, British Columbia. 



P. orophilas Merriam ................ Salmon River Mountains, Idaho. 



P. preblet Merriam .................. Longs Peak, Colorado. 



P. latimanus Merriam .............. Fort Chimo, Ungava, Labrador. 



P. ungava Merriam .................. Fort Chimo, Ungava, Labrador. 



P. longicaudm True. . . . ............. Marshfield, Coos County, Oregon. 



These fall naturally into three groups, each of which occupies 

 a different geographic region. The ungava group, containing 

 two well-marked yellow-faced species, ungava and latimanus, 

 ranges from Quebec and Labrador west at least as far as the 

 north shore of Lake Superior. The intermedius group, with 

 three slightly differentiated uniformly grayish or ochraceous 

 species, intermedius, orophilas. and preblei, occupies the moun 

 tains of British Columbia, Alberta, and the northwestern United 

 States. The third or longicaudus group is represented by one 

 species only, the very aberrant P. longicaudus of the humid coast 

 district of Oregon. 



The species of Phenacomys are voles of medium or small size. 

 With the exception of P. longicaudus, which is remarkable for its 

 very long tail, there is nothing in the external appearance of any 

 to distinguish them from small species of Microtus. They gen 

 erally inhabit dry, grassy plains and mountain parks, but P. 

 longicaudus appears to be strictly arboreal. At present all the 

 species definitely known are American. The determination of 

 the European fossil remains is open to question. f 



*The specimens examined in the present connection are distributed as 

 follows : U. S. National Museum, 64, including the types of P. longicaudus, 

 P. orophilus, P. truei, and P. preblei (all but two of these are in the Bio 

 logical Survey collection) ; Museum of the Canadian Geological and Nat 

 ural History Survey, 1 (type of P. intennedius] ; Merriam collection, !> 

 (types of P. celatus, P. ungava, and P. latimanas) ; Bangs collection, 16 

 P. ungava from Hamilton Inlet, Labrador; Miller collection, 7 P. latl- 

 titanuis from the north shore of Lake Superior, and 4 P. orophihi* from 

 Mount Baker, British Columbia (topotypes of P. ommonii*). 



fSee North American Fauna, No. 12, p. 40. 



