14 BAT-TRIBE. 
consists in the extraordinary development of the fingers, 
which are greatly elongated for the purpose; and upon 
which the skin is stretched like the silk on the rods of an 
umbrella.” This fossil, which forms the chief and central 
figure in cut 5, includes the distal end of the humerus, 
or arm-bone, the entire radius, or chief bone of the fore- 
arm, the little bones of the carpus, or wrist, the small 
thumb with its broad flattened phalanx for the pre- 
hensile claw, and the long and slender metacarpal bones, 
and a few of the phalanges of the fingers, which Professor 
Bell has so aptly compared to umbrella-rods. 
‘‘The hinder-toes,” continues the same author, “are 
short, of nearly equal length, and are chiefly used as sus- 
pending organs, the Bats hanging by them, from the trees 
or walls on which they rest, with the head downwards.” 
This character is likewise displayed in the well-preserved 
hinder limb of the skeleton figured, together with another 
peculiarity, viz., a slender rod of bone extending from the 
heel to sustain the inter-femoral web. 
Any one of these characters singly would suffice to 
determine the ordinal relations of the bony relics presenting 
them. To obtain a deeper insight into the affinities of the 
fossil, much closer and more minute comparisons must be 
instituted. In the specimen under consideration, the two 
pairs of incisors in the upper jaw, and the three pairs 
indicated by the sockets in the lower jaw, 6, where they are 
combined with two premolar teeth on each side, prove it to 
belong to the true Vespertiliones, and distinguish it from 
the Nycterides, which have but one premolar in each ramus 
of the lower jaw. In the Noctiliones there is only one pair 
of incisors in the lower jaw: in the Molossines, the Mega- 
derms, and the Rhinolophines, there is only one pair of 
incisors in the upper jaw: the Taphians have no upper 
incisors at all. 
