OCT., 1900.] MAMMALS OF THE YUKON KEGION. 38 



ability that the latter has a transcontinental range. Their skulls arc 

 large]- and have fuller braincases than those of either oreaa or cana- 

 densis. 



Peromyscus maniculatus arcticus (Mearns). Arctic White-footed Mouse. 



Ileupcroinyti Ifucupus ardicu-'i biennis, Bull. Xixi. Mus. Nat. Hist., N. Y., II, 285, Feb., 

 1890. 



A short-tailed white-footed mouse was found to be very common 

 from Lake Marsh to Lake Lebarge. Thirty specimens were secured, 

 most of them about the crevices of low ledges of rock along the lake 

 shores. The name arcticus is onh^ tentatively used for these speci- 

 mens, as its applicability can not be positively known until a series of 

 Lal^rador specimens is obtained. My specimens do not differ from 

 topotypes of arcticus^ and these in turn, as stated by Bangs, ^ do not 

 differ in color and size from t3q:)ical maniculatus. The description of 

 the skull of the Great Whale River specimen examined b}^ Bangs, how- 

 ever, does not agree well with the characters of the skulls of arcticus, 

 so it seems advisable to recognize arcticus as a subspecies of manicu- 

 latus. It is probable that more material will amply justify this treat- 

 ment of the western form. 



Neotoma saxamans sp. nov. Northern Bushy -tailed Rat. 



Typ<; from Be-nuett City, head of Lake Bennett, British Columbia. No. 98923, U. S. 

 Nat. Mus., Biological Survey Collection, $ ad. Collected June 19, 1899, by 

 W. H. Osgood. Original No., 462. (See Plate V, fig. 4. ) 



Characters. — Similar to Neotoma cinerea drummondi., but somewhat 

 darker: underparts pure white; skull strongly characterized. 



Color. — (Type:) Above, grayish fawn mixed with black, becoming 

 brighter on sides, Avhere the quantity of black is much diminished; 

 underparts and feet pure white; eyelids intense black with a limited 

 sooty area about them; nose and anterior cheeks ashy; tail slaty above, 

 white below. 



Skidl. — Similar to that of W. drumm/mdi (Plate V, fig. 3^) but with 

 interorbital space narrower; nasals narrower and more attenuate pos- 

 teriorly; maxillary arm of zygoma lighter; sphenopalatine vacuities 

 open; ventral surface of occipital with a high trenchant median ridge; 

 front of incisors very pale. 



Measurements. — Type (from dry skin): Total length 452; tail verte- 

 brae 192; hind foot 46. Skull of type: Basal length 52; zygomatic 

 breadth 20; interorbital width 5; length of nasals 23. 



Reniarks. — Neotoma saxamans differs from N. cinerea^ N occiden- 



lAm. NaturaHst, XXXII, 496, July, 1898. 



'^Neotoma c. columbiann Elliot does not differ eranially from N. cmerea, and there- 

 fore need not be considered in this connection. 

 ^No. 75907, IT. S. Nat. Mus., from Jasper House, Alberta. 

 4494— No. 19 3 



