80 BULLETIN NO. VII. 
tilionidz is considerable, is of itself not very deep, and ends in 
the most convex point of the tragus, whence the border runs 
upward and inward to the tip. The lower jaw is covered with 
short hairs, and has at its symphysis a small naked space 
which is gradually lost along the sides of the mouth. The pos- 
terior surface of the ear is covered with hair one-half its length, 
which extends upon the anterior production of the external 
border down to the angle of the mouth. 
The fur of the body is everywhere long and silky. Anteri- 
orly it is rather denser though not quite so long as that pos- 
teriorly. It is of a light russet red, tinged with yellow, being 
tipped with gray toward the neck, and varying to fawn color, 
in some specimens, toward the pubis. Fur of the same gen- 
eral hue extends from the body upon the alar membranes up 
to the base of the third finger of either side and blends with 
that upon the anterior surface of the interfemoral membrane 
at about the region of the tibiofemoral articulation. The hair 
upon the latter membrane runs down fully one-half its length 
in most specimens. The interbrachial expansion also possesses 
a sparse growth of yellowish fur. Posteriorly the fur is very 
long, and presents a richer appearance than anteriorly. The 
russet red color is here predominant in the majority of indi- 
viduals, though we meet with a great variety of hues of fawn, 
fawn-red, and yellowish cinereous. At each shoulder a con- 
spicuous white tuft of hair is seen; this is not elevated above 
the surrounding fur of the neck with which its whitish color 
gradually blends. 
The posterior surface of the alar membranesis less extensively 
furred along the brachial and digital regions than the anterior 
surface, being here almost altogether confined to longitudinal 
bands extending from the neck downwards across the inter- 
brachial membrane midway from the shoulder to the elbow, 
and thence continued along the sides of the body and external 
border of the tibia to the ankle and tarsus of either side. The 
dorsum of the fifth finger, for about one-third of its length, is 
covered with fine scattering hair. The basal joint of the 
thumb is decorated with a whitish tuft. 'The posterior surface 
of the interfemoral is very thickly covered over its whole area 
with fur of the same color as that of the body. The difference 
in hue of various individuals is owing chiefly to the colora- 
tion of the tips of the hair. Each hair is tinged as follows: 
The base dark plumbeous in color verging to black; the 
middle, a delicate yellowish-brown, passing outwards toward 
