8 Bangs — The Weasels of Eastern Nortli America. 



and nj)iHT li]is wiiitc; tail wiine color as upper parts, sometimes a little 

 paler below than above, becoming suddenly black at tip, and ending in a 

 long pencil of black hairs ; under fur a shade or two lighter than the long 

 hairs. Winter pelage : Pure wliite all over, with no yellowish tinge ; end 

 of tail jet black. The change to a white winter coat apparently takes place 

 over the entire range of the species. 



Size. — Average of five adult males from AUjerta and Saskatchewan: 

 total length, 445.5; tail vertebrae, 161; hind foot, 51.5. Average of five 

 adult females from Alberta, Saskatchewan, and North Dakota : total 

 length, 385; tail vertebrae, 139; hind foot, 43.5. 



Skull. — Short, broad, and massive, developing with age a strong sagittal 

 crest ; general shape of brain case, viewed from above, triangular, owing 

 to great width across mastoids and sharp constriction behind postorbital 

 processes ; postorbital processes well developed and conspicuous ; audital 

 bullae broad, deep, and short ; inflated squamosal much reduced and not 

 nearly flush with under surface of audital bullae ; distance from audital 

 bullae to jaostglenoid process very short; mandible large and heavy. 



The skull of P. longicauda resembles the skull of Putorius proper more 

 than that of the smaller members of the subgenus Gale. 



The dentition is normal, l)ut rather heavy. 



Remarks. — Putoriics longicauda. is easily told from all other 

 North American weasels. Its highly developed desert colora- 

 tion, large size, and long, graceful tail make it one of our finest 

 species. Specimens from Devil's lake. North Dakota, while refer- 

 able to this species, are rather darker than true longicauda and 

 are approaching its eastern subspecies spadix. 



P. longicauda and its allies seem to be less subject to the attacks 

 of the parasite that lives in tbe frontal sinuses of all the weasels 

 than the other members of the subgenus Gale. The sexual differ- 

 ence in size is not so great in P. hmgicaudd as in most of the otber 

 species. 



Putorius longicauda spadix snbsp. nov. 



Type from Fort Snelling, Minn., No. l^H, male, yg. ad., American 

 Museum Nat. Hist., New York, col. by Dr. E. A. Mearns, U. S. A., June 

 25, 1889. Original number, 812. 



Geographic dhtribution. — The western edge of the eastern forest Ijelt in 

 Minnesota (Fort Snelling and Elk river). The subsjiecies probably ranges 

 north and south of this region. Further west, where the open, treeless 

 plains are reached, it passes into true longicauda. 



General characters. — Similar to true longicauda, from which it differs in 

 color only. 



Color. — Summer pelage: Upper parts Front's brown, not very different 

 from the color of P. novehorncensia, but perhajis a little brighter — very dif- 

 ferent from the yellowish and clay color of true longicauda. Under parts 

 in the type white, with a faint greenish yellow tinge. In two topotypes 



