634 Wisconsin Academy of Sciences, Arts, and Letters. 
very well with the mean of these measurements; that their 
apices are approximately perpendicular to the centers of their 
bases. The smaller the number of specimens used in any table 
the less, as a general thing, do the binomial curves approximate 
this correct proportion; although, in some instances, curves of 
multiple apices show in measurements of considerable series. 
Notwithstanding the general correspondence in proportions 
among these specimens, exceptions are not rare; and in some 
instances the graphs have nearly reversed themselves. A re¬ 
markable instance is seen in M or mo ops megalophylla between 
the specimens from number 814 to 822 in which the proportions 
of length and tail show great discrepancies. Various instances 
can be found in any of the tables where a member considerably 
above the mean of its class is coupled with another decidedly 
below its mean. 
Mormoops megalophylla • Peters. 
Thirty-three specimens collected near Jalapa, Veracruz, Feb¬ 
ruary 23, 1891, by H. L. Ward and 0. M. T'eran. 
Other specimens of this species were taken at Cerro de Jojutla, 
District of Juarez, Morelos. 
This species, Natailus stramineus, Chilonycteris rubiginosa, 
and Dermonotus daojyi were found in a remarkable lava tunnel 
some miles northeast of Jalapa, Veracruz, in the bottom of the 
canon of Actopan, within the tierra caliente or hot zone. The 
nearest place that the lava could have come from was the vol¬ 
cano of Perote about 30 miles west, and some 3,000 feet above, 
near which similar lava tunnels occur. .The only apparent 
entrance to this one was through a hole about a yard in diameter 
formed by the breaking through of the roof at one point. The 
cave or tunnel is known to the inhabitants of this district be¬ 
cause of the great number of bats that nightly issue from this 
hole in the nearly level ground, and from them has received the 
not inappropriate name of El Infernillo, or the little hell. As 
far as I could ascertain no one had entered the tunnel previous 
to my visit. My assistant, T'eran, and myself let ourselves down 
by a rope, which we tied to a piece of wood placed across the 
opening, until we reached a conical pile of rocks formed by the 
breaking down of the roof some 20 or 30 feet above. At this 
