103 
11. Micro tus mordax mordax (Merriam) Mountain Long-tailed Vole 
One of these mice taken in habitat of Yakutat voles. Possible that a 
mouse colony found later, considerably higher than this locality, and just 
beyond line of willow-clumps, may have belonged to this form. Colony 
discovered in August too late to lay a trap-line. 
Specimen: One, No. 5652, 9 204-82-21. Chitina River glacier. A large species 
which reaches nearly its northern limit in this section. Known by long tail about one- 
third of total length. 
Colour greyish; back greyish bistre; sides dull grey; belly washed with whitish; nose 
dusky. Tail bicolour, dusky above, soiled whitish above. Feet plumbeous. Second 
upper molar with four closed sections, posterior open; first lower molar with five closed 
triangles; five inner and four outer salient angles back of anterior loop; third lower molar 
with anterior crescent, three closed triangles, and posterior loop with two inner salient 
angles; second and third lower molars each with three outer and three inner salient angles 
12. Erethizon epixanthum myops Merriam Alaska Porcupine 
Only four specimens seen and all taken. Three of these invaded camp, 
May 22 and 25, in night in both cases, and raised a disturbance by gnawing 
charred wood. Fourth taken near timber-line June 12, where on a rainy 
day he was found sitting 15 feet aloft on a matting of dead spruce twigs of a 
leaning windfall. All males, one only being adult. Three somewhat 
smaller and darker than adult, and sex organs, by comparison, but half 
developed — testes being still within body wall. 
Porcupine work upon bark of smaller spruce seen occasionally in woods, 
but fresh work during summer not noted. 
Specimens: Four (two skins and four skulls), May 24, two skins with skulls. 
No. 5621, c? ‘50-170-97. Specimen with whole front and sides of head brownish 
black; top of head and nape with long, light yellow hairs forming a sort of ruff; whole 
dorsal region, flanks, and legs blackish, becoming dull brown on belly; a few long, sparse, 
yellow hairs on legs; rump and tail a mixture of black and yellow hairs. In coloration 
this specimen closely resembles typical E. e. nigrescens Allen. 
No. 5622, 800-220-114. Larger than preceding. Front and sides of head pale 
fuscous brown; top of head and nape with a run of rather pale yellow hairs; dorsal, flanks, 
and legs, a dull mixture of brownish and very pale yellow hairs; a few yellow hairs on legs; 
tail black along median line, fringed with long, whitish yellow hairs. Specimen corre- 
sponds to description of E. e. myops in having general colour effect yellow. Much more 
yellowish and brighter in tint than any specimens in a large series of nigrescens from Teslin 
Lake region, southern Yukon. 
May 25, No. 5623, o', skull only. 
June 12, No. 5638, d”, skull only. 
All skulls adult, but No. 5638 very old with sutures nearly obliterated. Nos. 5622 
and 5623 have zygomata nearly straight, No. 5638 slightly bowed, and No. 5621 very 
much bowed outward throughout whole length. Dr. Merriam, in his original description 
of E. e. myops, gives outward bowed zygomata as a character of myops. Specimens vary 
somewhat in size of occipital crests, these being well developed in Nos. 5622 and 5638, 
small in No. 5623, and very slight in No. 5621. Sagittal crests well developed in Nos. 
5622 and 5623, but smaller in Nos. 5621 and 5638. Skulls all show a marked depression in 
fronto-parietal region. Outer wall of anteorbital vacuity, from side, slightly concave and 
sloping a little backward inferiorly. Skulls of porcupines vary greatly individually and 
from age, but on whole these specimens fairly uniform in character, approaching somewhat 
to nigrescens type, with which form they are probably intergrades. 
13. Ochotona collaris (Nelson) Collared Pika 
Pikas present sparingly in all suitable rock slides at about 5,000 feet 
and over, but this animal never observed below timber-line anywhere on 
range. On only one occasion more than two of little animals found in a 
slide, three being seen high above Trail End, July 31. 
