A MONOGRAPH OF THE BATS OF NORTH AMERICA. 145 



^'6 basal black is here absent. The back of the toot is covered with 

 r of the same character as on the interfemoral membrane. A patch 

 of white hair is seen overlying the first metacarpal bone. 



The abrupt contrast seen at the side of the neck between the dorsal 

 and the ventral colors, the long stretch of the dorsal color that covers 

 the ear and extends with its lower forward curve to near the angle of 

 the mouth, the raised longitudinal fold of integument, tend to make 

 this xiart of the body of special interest. 



On the venter the hair is not of the uniform shade of the dorsum, 

 1 ut presents two divisions, the first in the region of the space beneath 

 the jaws and in front of the neck; the second, that of the front of the 

 chest, the abdomen, and the pubis. The first is of a delicate shade of 

 •usset red, verging to yellow; the second is of a grayer or whiter tinge, 

 especially at the tips of the hair. The sides are often pure salmon. 

 The basal black and shaft of buff are the sailie as on the dorsum, but 

 the long gray tip is best developed on the venter. The salmon- tinted hairs 

 of the side are without yellow on the shafts and are often without gray 

 tips. A conspicuous white patch is seen on the venter of prebrachium 

 as this membrane joins the body. In some individuals a ring like band 

 of white is continuous with these patches across the pectoral region. 

 The sides of the neck are particularly richly colored for the red and 

 white effects are here abruj)tly demarcated. In Southern examples the 

 gray of the abdomen predominates over the red and salmon. In Mex 

 lean varieties the entire venter assumes a gray tinge with warm sienna 

 brown interspersed. The hair of the membranes is less develoi)ed on 

 the interfemoral membrane, but is more developed on the wing mem- 

 brane than is the case on the dorsum. On the interfemoral membrane 

 short, woolly, sparsely arranged unicolored fur is seen at the basal half 

 only. From the knee the same character of fur extends to the third 

 digit from the side of the body for a distance equal to one-third of the 

 width of the wing. The color is dull salmon. 



The varieties of coloration are found in the subtip and tip of the hair; 

 they may be named the red, the dark brown, and the gray. The red is 

 confined to the subtip and is accomiianied with a bright buff" shaft and 

 no ashy tip or so slight a disposition to ash as not to interfere with the 

 prevalent color. The dark brown retains a dull old gold or oc^ "^r shaft, 

 ; with a subtip of this color or of old gold; in this variety the membranes 

 are from dark brown to nearly black; the gray color, to a gray-brown 

 subtip, a fawn shaft, and a long gray tip ; no ashy hue is anywhere seen. 



These differences do not correlate with any structural peculiarities or 

 with contrasts in measurements. Unfortunately many of the more strik- 

 ing are from examples which are without locality. One gray specimen 

 was from Louisiana. In a specimen from Mcmnt Pleasant, sent me for 

 inspection by Mr. G. S. Miller, jr., the colors were somber, being of a 

 dull maroon mottled Avitli black, remarkably like the display of colors 

 in A. semotci^ from the Sandwich Islands. 

 441— No. 43 10 



