ALLEN — BATS FROM MOUNT WHITNEY 
3 
has a pronounced white border, narrow at the tip of the wing and not sharply 
defined, but from the tip of the fifth finger to the tarsus, it is broad (1.5 mm. 
in the dry skin), very sharply and contrastingly marked off. The uropatagium 
is dusky on the basal third, passing into whitish on the distal two thirds, with a 
clearer white edge. 
Membranes. — The ears and tragus are practically as in M. lucifugus, and 
minutely haired. The fur of the body extends very slightly on to the base of the 
uropatagium, but is sharply limited at the sides of the body. The foot is rela- 
tively large as in M. lucifugus, the calcar long and slender, unkeeled, ending in 
a minute projecting lobule. The extreme tip of the tail is free. 
Skull. — Unfortunately the skull of the type has been temporarily mislaid. 
The skull of a second specimen, however, (1023, coll, of A. B. Howell) from 
Mono County, California corresponds closely in size and shape with that of M. 
lucifugus altipetens, but is at once distinguished by the relatively larger and 
blunter first and second upper premolars (pm^, pm^). In M. lucifugus and its 
western race both are fully visible in side view, and stand practically in the line 
of the tooth row, the posterior tooth with perhaps one half the cross-section area 
of the anterior. In M. albicinctus, however, the larger anterior tooth is distinctly 
drawn in from the tooth row and shifted slightly forward, so that the anterior third 
of its base is nearly concealed by the base of the canine when viewed in profile. 
The second premolar is distinctly larger relatively, in cross section, than in M. 
lucifugus. As in the latter, and in contrast to M. subulatus, the lower incisors are 
but very slightly imbricate. 
Measurements. — The type measured before skinning: total length, 86 mm.; 
tail, 42.5; hind foot, 9; ear from meatus, 15; forearm, 37; tibia (dry), 16. The 
specimen collected by Mr. A. B. Howell in Mono County, California, measured: 
total length, 91 mm. ; tail, 41 ; hind foot, 11 ; ear, 14; alar expanse, 255. Its fore- 
arm measures 38 mm., tibia, 17.5. 
The skull of the latter specimen (1023, coll. A. B. Howell), measures: greatest 
length, 15; basal length, 12.5; palatal length, 7; upper tooth row, U to m^, 6.5; 
width outside m^, 5.8; interorbital width, 3.8; zygomatic width, 9; mastoid width, 
7.5; lower tooth row, i\ to m3, 7. 
Remarks . — This very beautiM new species is at once distinguished 
from any of the described forms of North American Myotis by its pale 
buff coloration above, contrasting with the white lower surface, and 
by the conspicuous and sharply defined white border of the wing 
membranes, and the silvery uropatagium. 
The type was shot at dusk as it was fiying down the slope above 
our camp at 11,000 feet on Mount Whitney. The locality was just 
above a clump 'of pines that formed the upper limit of timber at the 
lower end of a large valley encroaching upon the main peak. A rush- 
ing mountain stream dashed past at this point and a large snow bank 
still remained near by in mid-July. 
The skull of this specimen after brief examination, was put aside for 
cleaning but has been unfortunately mislaid. I had hesitated to de- 
