dactylopatagium
Dactylopatagium is a wing membrane of bats (order Chiroptera). It is the portion of the patagium that extends between the digits (fingers) II–V and the body, forming the principal surface used in flight. The dactylopatagium is continuous with the propatagium at the shoulder and with the plagiopatagium along the wing’s trailing edge, and it is supported by the bones of the forelimb, especially the metacarpals and phalanges. Its skin is thin and hairless, and highly elastic, allowing the wing to fold when not in use.
In bats, the size and shape of the dactylopatagium vary among species and are related to flight
Functionally, the dactylopatagium provides lift and wing camber, distributes aerodynamic loads across the wing, and participates