836 The American Naturalist. [September, 
Two specimens, kindly sent me by Dr. Allen, from Santa Ysabel, 
are evidently the same species. They are more fully adult than the 
San Bernardino specimen, and, like other San Diego County skins, are 
blacker above. Their external and cranial characters confirm their 
identity with mine as contrasted with longicaudus. Owing to the more 
typical character of Dr. Allen’s specimens, I have chosen one of them 
for the type in preference to my own. Duplicates of pallidus from the 
San Bernardino Valley southward, will most probably confirm its good 
specific characters. Its alliance to megalotis is certainly more remote 
than with longicaudus. Its possible identity with montanus is very 
doubtful on geographical grounds alone, the latter being probably, as 
Dr. Allen indicates, an eastern Rocky Mountain form of humilis. Dr. 
Allen's azteeus from New Mexico differs from it in larger size, rela- 
tively much shorter tail, less buffy color, and in eranial proportions. 
In external measurements pallidus is much shorter and smaller- 
bodied than /ongieaudus and has smaller feet. In skull measurements 
it shows the same diminution in length with greater relative zygomatic 
breadth and a blunter, less attenuated rostrum. The relative length 
of mandible to height of coronoid process above angle in pallidus is in 
the same direction. The coronoid process in pallidus is sharply 
hooked, in /ongicaudus it is bluntly recurved. 
These features are shown in the following table : 
Bopy MEASUREMENTS. 
longicaudus | pallidus 
(4 adults) (3 adults) 
Total length 153. 138. 
Length of tail vertebree 80. T9. 
oS hind fos 18. 16. 
“ — * ear, from crown (from skin).......... 10.5 11. 
SKULL MEASUREMENTS. 
Basilar length (of Hensel) | 15.6 14.6 
Greatest zygomatie breadth 9.8 10.2 
Interorbital constricti 3. 3. 
Length of nasals 7.8 7.1 
Total length of skull 20.5 19.2 
Length of mandible 12. A. 
. Height of coronoid process from angle. . 61 5. 
—SAMUEL N. Ruoaps. 
