30 BULLETIN NO. VII. 



tilionidae 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 membranes is 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 



