﻿LASIURUS CINEREL'S. 



113 



ill borealis and without trace of uotch ou anterior border. Margin of 

 ear membrane dark brown or blackisli. Outer side of ear densely furred 

 to a little bej'O'ud middle. Inner side witli conspicuous patcli of yellow- 

 isli hairs above and in front of middle and a border of similar hairs along- 

 lower x^art of anterior edge. 



Tragus shaped as iui. borealis, covered with sparse coating of hairs 

 on outer side. 



Membranes. — In form and attachment the membranes are as in L. 

 borealis. 



Feet. — Foot about half as long as tibia 5 dorsal side thickly furred. 

 Calcar twice as long as foot and slightly shorter than free border of 

 interfeinoral membrane. It is distinctly though narrowly keeled on 

 posterior edge, and usually lobed at tip. The terminal lobe is very 

 variable, and may be well developed on 

 one side and absent on the other. 



Fur and color. — The fur is distributed 

 mnch as in L. borealis. As in that species, 

 it is distinctly longer on neck than on back, 

 thus forming a ruff. On the neck it aver- 

 ages about 15 mm. in length, on the back 

 11 mm. General color, a mixture of light 

 yellowish brown, deep umber brown, and 

 white, the yellowish brown clear and un- 

 mixed on throat, head, and under side of 

 membranes, the umber brown predominat- 

 ing on back and dorsal surface of interfem- 

 oral membrane, where, however, the hairs 

 are mostly tipped with silvery white, some- 

 times to so great an extent as nearly to 

 conceal the dark tints beneath. Lips, 

 chin, and cheeks sprinkled with short blackish hairs. Yentral surfiue 

 with white predominating on belly, between which and yellow of throat 

 is a band in which the umber brown is more consx3icuous than else- 

 where on the under parts. Tufts of fur at bases of thumb, fifth finger, 

 and forearm, light yellowish brown, like fur on under side of wing 

 membranes. On middle of back the individual hairs are colored as 

 follows: Deep plumbeous at base; light yellowish brown (shading 

 toward umber distally) through middle half 5 umber brown subapically 5 

 silvery white at tip. 



Color variation is considerable, but never enough to obscure the char- 

 acters of the species. It aj)pears to be wholly independent of locality, 

 as skins from such widely separated localities as Minnesota and south- 

 ern California are practically indistinguishable. 



One skin from the Santee Elver, South Carolina, has the dusky tints 

 throughout the pelage so intensified and extended as to suggest melan- 

 ^2772— No, 13 8 



Fig. 31.— Skull of Lasinrus cinereus 

 (X2). ^ 



