In view of the very interesting information about pterodactyls contained in the foregoing paper by Dr. Hankin and Mr. Watson it will be worth while to endeavour to reconstruct the animal and to ascertain as far as possible the effect of the various adjustments upon the shape of the membrane which forms the wing.

This can best be accomplished by a study of the drawings accompanying this paper.

In the first place, it is important to remember that the wing membrane (plainly visible in some of the smaller fossils) doubtless resembled that of a bat in being extremely extensible and elastic. Possibly it had muscles attached to it which could tighten it in various directions and possibly increase and diminish camber. Air pressure upon this membrane would be certain to make the back margin of the wing a curved line with the convexity upward and the front margin of the wing (formed chiefly by the supporting bones) would have to follow this curved line more or less closely, otherwise the angle of incidence would vary excessively in different parts of the wing.