SOPER-ORDER INEDUCABILIA. 
ORDER CHIROPTERA. 
The Bats have the anterior members adapted for flight; the humerus 
is long and slender, the ulna rudimentary, attached to the curved radius, 
which constitutes the bulk of the forearm ; the carpus is composed of six 
bones ; the metacarpal bones, five in number, are much elongated, as are 
the phalanges, which are two to five in number—usually two. The 
bones of the arm and hand support a thin, leathery skin, arising from 
the sides of the body and extending backwards on the hind members 
down to their tarsi, and including the tail. Tail usually of nine joints; 
the interfemoral membrane may or may not include the tip of the tail. 
The nervous system is highly developed, especially the special senses of 
hearing and touch. The ears, externally and internally, are highly per- 
fected. The auricles of the insectivorous Bats are frequently much larger 
than the head, and of great variety of shapes, their variations in form 
being of great importance in classification. The nose is, in many Bats, 
the seat of extensive dermal growths, composed of reduplications of the 
skin, which probably act conjointly with the wing-membranes to aug- 
ment the sense of touch. The skeleton is noted for its lightness and 
tenuity, the bones of the Little Brown Bat weighing but eleven grains. 
The teeth vary from thirty to thirty eight, which, combined with the 
marked differences in their contour, furnish important characters in 
classification. The sternum is of great strength and excessive develop- 
ment, the immense power employed in their active flight necessitating 
the presence of strong osseous points for the attachment of muscles. The 
whole structure is adapted to the habits of the animal. The great devel- 
opment of the ribs, sternum, and scapula, for the attachment of muscles 
of flight; tne length and strength of the clavicle, and the long bones of 
the anterior extremity fulfill an:obvious purpose. The digestive appa- 
ratus is simple, corresponding to their animal regimen. Some foreign 
species are strictly frugivorous; our species subsist on insects, mainly 
the crepuscular and nocturnal kinds, as Gnats, Moths, Mosquitoes, and 
even the heavily mailed Coleoptera. 
“The disappearance of the birds of day,” says Dr. Allen, “is a signal 
for the advent of the dusky host, which, as 1t were, temporarily relieve 
from duty their more brilliant rivals in guarding the interests of Na- 
ture.” 
6 
