24 NORTH AMERICAN FAUNA. [No. 11. 



the same, si/e. Moreover, the ]>ostorl>it;il processes are longer and more 

 slender than in any female, of arizonenttiH I have examined from either 

 the Rocky Mountain or Sierra systems. Externally the St. George 

 specimen differs from typical ar/.:o;/n/.s-/.s in the following particulars: 

 Yellow of underparts more strongly tinged with ochraceous; white of 

 upper lip narrow and not reaching around anteriorly; brown of upper 

 parts reaching down on outer side of arm to wrist; a small brown spot 

 bearing two bristles just behind each corner of mouth. In this respect, 

 and this only, it resembles axmthogenys; there is no trace of white on 

 the cheeks or between the eyes. 



MeamtreiHcnts. Average of 5 males from the Rocky Mountains: 

 Total length, 385; tail vertebne, 144; hind foot, 44.5. Average of 4 

 females: Total length, 358; tail vertebne, 130; hind foot, 40. 



PUTORIUS ALLENI sp. nov. Black Hills Weasel. 



Type from Ouster, Black Hills, South Dakota. No. *|j6, $ ad., Merriani collection. 

 Collected July 12, 1888, by Vernon Bailey. Original No. 90. 



Geographic distribution. Black Hills, South Dakota. 



Characters. Similar to P. arizoncnxift in size and general characters, 

 but upper parts more suffused with yellowish and andital bulhe flatter. 



Color. Upper parts from occiput to black tip of tail golden or yel- 

 lowish-brown, in some lights with an olivaceous tinge; head dark 

 brown, without yellowish tinge; upper lip and chin white; rest of 

 underparts, including inner sides of legs, whole of fore feet, toes of 

 hind feet and under side of basal part of tail, intense butty yellow. 



Cranial characters. Skull similar to that of arizoHCHHix, but audital 

 bailee much flatter and somewhat smaller; brain case slightly flatter 

 and bulging laterally immediately behind constriction; frontal some- 

 what broader interorbitally; skull as a whole shorter. The skull of an 

 old female (No. 7441, Am. Mus. Nat. Hist.) is much smaller than the 

 male, and the audital bulla 1 are narrow and not flattened. In both 

 sexes the postorbital processes are strongly developed. 



Remark*. Futorius alleni is an isolated and only slightly differen- 

 tiated form of P. arizoncnsis, from which it is completely cut off geo- 

 graphically. It is surrounded on all sides by the large weasel of the 

 plains, P. lon<jicau<la. In worn summer pelage the color differences 

 that distinguish it from arizonensix are not apparent. 



I take pleasure in naming the species in honor of Dr. J. A. Allen, 

 of the American Museum of Natural History, New York, who has 

 recently published an important paper on the mammals of the Black 

 Hills, and to whom I am indebted for the loan of three additional 

 specimens. 



Measurements (of type specimen, male adult). Total length, 37H; tail 

 vertebra?, 137; hind foot, 44. 



