Calcar: A long, bony spur on the bat's ankle that helps support the tail membrane.
Forearm, fingers, and thumb: Bats' forelimbs include most of the same components as those of other mammals, but the hands and fingers are elongated to support and manipulate the wings.
Nose leaf: A flap of skin above the nostrils of some bats. Among New World species with this feature, it usually is triangular and rises vertically from the tip of the nose.
Tail membrane: Also called the "interfemoral membrane," this spans the area between a bat's legs and tail.
Tragus: A flap of skin at the base of the external ear. It often rises vertically like a small sword.
Wing membrane: A thin double layer of skin that forms the bat's flying surface.