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. 1 ' 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, 1 ' 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, 5, where they are 

 combined with two premolar teeth on each side, prove it to 

 belong to the true Vespertilioms, 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 TapMans have no upper 

 incisors at all. 



