648 Wisconsin Academy of Sciences, Arts, and Letters. 
15 :11 and 13 :12. The third metacarpal may he longer, eqnal 
to or shorter than either the fourth or fifth. Between the fourth 
metacarpal and its first phalanx the extremes are between 42 :11 
and 38:12. Between the first and second phalanges of this 
fourth digit the variation is 11:10 and 11:7. The fourth meta¬ 
carpal is usually slightly longer than the fifth but may be the 
same length. The variation between the fifth metacarpal and 
its first phalanx is expressed by 36 :11 and 39 :9. Between the 
first and second phalanges of the fifth digit the extremes are 10 :7 
and 10 :5. 
This species I also collected at Cuernavaca, Morelos and at Ix- 
tapalapa, Federal District, where it occurred in small numbers. 
At Las Vegas, a little hamlet on the northern slope of the Vol¬ 
cano of Perote, not far from Jalapa, Veracruz, I found this bat 
in great numbers and my collecting w T as limited only by my 
desires. 
Here was a lava field honeycombed by tunnels formed by the 
running out of the molten interior after the surface had become 
too cool to flow. The tunnels were approximately parallel and 
were frequently superimposed. Three were the largest number 
that were noted in the same vertical plane. In many cases the 
vertical diameters were thirty-five feet or more. The floors w 7 ere 
comparatively smooth and flat, with the walls springing at about 
right angles from them. Some of these tunnels were fifty feet 
or more in width and in section nearly as regular and with as 
finely arched roofs as if artificially constructed. Entrance was 
had through holes in the roofs that were probably caused by 
earthquakes breaking the thin shells. Frequently superimposed 
tunnels were united in the same manner, and rapid walking with 
the faint and uncertain light of unprotected candles was some¬ 
what dangerous, as it was not easy to see that the bottom of a 
tunnel had fallen out until one was close to the brim. The 
temperature of these tunnels was quite low and the bats were 
mostly found clinging to the ceilings in a state of lethargy. 
They were not much disturbed by our lights nor was it necessary 
to be cautious in approaching them. The gun was used only to 
determine the identity of those out of reach. When held in the 
hand for a few moments they woke up, gave utterance to high 
pitched squeaks and struggled to escape. They were mild man¬ 
nered and not inclined to bite. 
Although during the three days that I hunted this region I 
