14 BANGS —_ LABRADOR MAMMALS Ee 
A. monax. Top of head, dark mars brown to blackish, an irregular whitish 
mark extending across top of nose between whiskers; sides of head, chin and 
lips, grizzled with pale yellowish. Under parts: hairs dark vandyke brown at 
base, tipped with reddish brown or dull ferruginous; feet and hands black, 
this color extending a short distance up legs and arms; tail brownish black, 
only a very few of the hairs tipped with light brown. 
The other specimens agree closely with the type. Some are, however, more 
marked about fore shoulders, chest and under surface of neck, with dull dark 
ferruginous (almost chestnut); and in two examples the light-colored mark 
across the nose is less conspicuous. 
Cranial and dental characters—The skull is wide and short, much 
depressed between postorbital processes, and develops a strong sagittal crest 
with age; rostrum short and heavy; nasals short and very wide, especially so 
posteriorly; palate narrow, the sides less parallel, coming together more 
toward posterior end, than in 4. monxax. Molars large, but similar to those 
of A. monax; first upper premolar larger than usual in 4. monax; incisors 
white; outer faces of incisors roughened by numerous little parallel grooves, 
as in A. pruinosus. (The incisors of 4. monax are usually quite smooth.) 
Measurements (in millimeters). 
No. Sex and Date Total Tail Hind 
age length  vertebre foot 
7971, type S old ad. July 13, ’98 559 136 85 
7969 ? old ad. July 4, ’98 554 145 77 
7968 Q ad. July 7, ’98 496 123 80 
7972 & ad. Sept. 30, ’98 480 on 85 
7973 2 yg. Aug. 9, ’98 385 115 79 
Skull, type, ss middle-aged adult: basal length, 81.4; occipitonasal length, 
84.2; zygomatic width, 59.6; mastoid width, 41.4; interorbital width, 23.8; 
width across postorbital processes, 39.6; width behind postorbital processes, 
16.4; width of rostrum, 19.; length of nasals, 33.4; greatest width of nasals, 
I5.; greatest width of nasals behind ascending branches of maxilla, 1r.; width 
of palate, at alveoli of first upper premolars, 14.2; at alveoli of last upper 
molars, 11.2; upper molar series, alveoli, 21.2; length of single half of man- 
dible, 66. mm. 
Remarks. ‘The Labrador woodchuck appears to be a distinct 
species, differing widely from true Arctomys monax, and quite as 
much from the Canadian form of that species—the Quebec 
Marmot of Pennant — whatever name may apply to that animal. 
Mr. Doane reports Avctomys ignavus to be common at Black Bay, 
but, so far as I know, the specimens he collected there are the 
