EXTERNAL APPEARANCE. H 



the buff hairs become more numerous, so that on the sides of the l)ody and on 

 the forearm they produce a clear buff or cream buff. This color of the sides 

 extends ventrally from the abdominal region to the upper part of the chest 

 where it passes into a deep ferruginous, almost chestnut, over the ventral surface 

 of the throat, upper chest, liases of the fore limbs and dorsally to the sides of the 

 neck. The inguinal region also is ferruginous. The short hairs of the feet and 

 distal portion of the snout are of the same buffy color as tiie venter, with a 

 slight admixture of ferruginous hairs around the mouth. A whitish nuchal 

 spot, about 15 by 10 nmi. in extent, is present in all but one of the specimens, 

 and seems to be a characteristic of the species. The presence of a white nuchal 

 spot is due to the failure to meet of the two lateral pigment areas whose centers 

 are on the sides of the neck, as has been elsewhere indicated by the writer. The 

 condition of partial albinism thus produced has here become fairly permanent, 

 so as to result in a definite pattern. A similar restriction of the dermal pigment 

 of the tail has taken place, so that a varj-ing length, usually nearly the chstal half, 

 is white. 



Variations from the type of coloration above described occur through an 

 increase or a decrease in the intensity of the pigment. One female shows a 

 maximum of increase in the black of the dorsum. This color is deep on the head 

 and extends to the elbows on each side, while on the back the admixture of 

 buffy hairs is very slight until well down on the sides of the body the clear buff 

 area is reached. The white nuchal spot exists in this specimen as a few scattered 

 hairs, hardly noticeable. Ventrally tlie lower surface of the forearm and the 

 inguinal region from tiljia to tibia is suffused with ferruginous. 



The opposite extreme is shown by another female in which the black is so 

 dilute, not only on the dorsal area as a whole, but in the separate hairs, that it 

 appears as a cUstinct brownish, nearly drab of Ridgway's Nomenclature of colors, 

 grizzled with buff hairs. The latter become slightly tinged with rufous on the 

 sides and venter. 



The ferruginous tint (Plate 2) is exceptionally well developed in two large 

 and apparently old females and in a third smaller animal, an adult male. In 

 the brighter of the two old females the buffy hairs of the back and sides of the 

 head and body and on all but the mid-ventral region are replaced by ferruginous, 

 even the nuchal spot being of this tint. The ventral portion of the chest and 

 the lower throat where the ferruginous is brightest in other specimens, have in 

 this example become so intensified that they are nearly black. The third bright 

 specimen above mentioned is the most brilliant. The dark throat area is nearly 



