48 



NORTH AMEEICAJ^- FAUN-A. 



[no. 39. 



Color. — Winter ^pelage: Upperparts uniform dark rustj ochraceous 

 or snuff brown; nose dusky; underparts light buffy ochraceous; feet, 

 chin, and often cheeks and spots on belly white. Summer pelage: 

 Upperparts dark cinnanion; underparts clear bright cinnamon. 



STcull. — Low and wide with short, wide braincase, wide-spreading 

 zygomatic arches, widest posteriorly, and wide, quadrate, or trian- 

 gular interparietal; nasals short, deeply emarginate; buUse small; 

 pterygoids narrowly V-shaped. Dentition very light; incisors slender, 

 mainly white or white tipped and projecting far beyond nasals and 

 premaxillge. 



Measurements. — Type (young Total length, 221; tail verte- 



brse, 68; hind foot, 29. Topotype (old <^)\ 246, 72, 32. Average 

 of 4 topotypes (females) : 188, 60, 28. Sl<:uTl (of type) : Basal length, 

 36; nasals, 13; zygomatic breadth, 26; mastoid breadth, 19; inter- 

 orbital breadth, 6.5; alveolar length of upper molar series, 7. Skull 

 of topotype (old <S) \ 41, 15.8, 29, 23.5, 6, 8. 



Remarks. — Typical leucodon differs widely from typical hott8e,hnt 

 as the gap is largely bridged by the somewhat divergent characters 

 of navus, and the chain of intergradation between the two extremes 

 is complete, there is ample ground for grouping not only leucodon 

 but navus and mewa as subspecies under hotts£. Only specimens 

 from the Rogue River Valley can be considered typical of leucodon, 

 but in spite of much variation specimens occurring over a wide range 

 of rough mountain, valley, and foothill country south to Fairfield, 

 Cal., can better be referred to leucodon than to any other form. 

 Skins of Fairfield specimens are indistinguishable from topotypes of 

 leucodon, but the skulls are close to navus. The principal variation 

 over this range is in a reversion toward the cranial characters of 

 hottse to the southward and a brightening of color in the less humid 

 interior. These brighter-colored specimens are externally very simi- 

 lar to tyj)icQl fulvus of the San Francisco Mountain plateau region of 

 Arizona, but comparison of skulls shows that the resemblance is 

 only superficial. Specimens from Hoopa Valley and Cuddeback are 

 clearly intermediate between leucodon and laticeps but are listed 

 under leucodon. Those from Cuddeback also strongly suggest hottx 

 but are rather small and in this approach minor. 



Specimens examined.— -Totsii number, 313, as follows: 



California: Baird, 3; Battle Creek, 2; Big Valley Mountains, 12; Bartlett Moun- 

 tain, 5; Berger Creek (Mendocino County), 1; Blue Canyon, 1; Briceland, 6; 

 Burney, 5; Cahto, 1; Calistoga, 2; Cassel, 1; Cuddeback, 9; Dana, 4; Downie- 

 ville, 1'; Dutch Flat, 2; Edge wood (Shasta Valley), 2; Eel River (head of, 

 near South Yolla Bolly Mountain), 1; Fairfield, 6; Fair Oaks, 13; Fall River 

 Mills, 2; Fort Jones, 1; Fyffe, 5; Gazelle, 6; Genesee, 3; Glen Ellen, 2; Gold 

 Run, 6; Goosenest Mountain (Shasta Valley), 1; Greenville, 1; Hayden Hill, 1; 

 Helena, 26; Hoopa Valley, 7; Hornbrook, 10; Indian Valley (Lassen County), 

 2; Lakeport, 1; Laytonville, 1; Lower Lake, 12; Mad River, near Kunz (Trinity 

 County), 6; Mountain House (Butte County), 8; Mount George, 1; Mount 



