We should regard this position as natural but for the long wing-finger hanging far down the sides. If it were to creep along it would have the same difficulties as a bat, and the length and weight of the head, as well as the proportional weakness of the bind limb, make it improbable that they progressed by leaping. These animals made use of their claws only to hang on to rocks and trees and to climb up steep cliffs. They could fly with their wings, and keep themselves aloft in order to catch insects or sea animals. The wide throat and the weak and high supports of the jaw-bone make it probable that they only used their teeth to capture their prey and not to mince it. By means of their long neck, which they usually bore curved backward in order to keep their balance, they could stretch out their head to their prey and change their centre of gravity, and so fly in different positions. The fundamental type of the Crocodile and Monitor leads us to suspect that they had a skin covered with scales. The approximation to the shape of the Bird makes it probable that they were feathered. And the whole outline, similar to that of the Bat, leads to the supposition that they were covered with hair, like the Monotremes. Goldfuss thinks he has got a clear insight into the covering of the body and the whole condition of the wing in examining the Pt. crassirostris. And the soft state of the stone near the bones he attributes to the presence of the soft parts of the animal; and supposes that on the original folds of the wing-membrane are to be seen tufts and bunches of curved hair directed downward and sideway[G]. And on the principal slab he finds evidence that the Pterodactyle had a mane on the neck like a horse. The tufts on the counter slab have some similarity with the feathers of the ostrich. Some very tender impressions on both plates still more resemble feathers. He recognizes the outline and faint diverging rays of a bird's feather, but never sees a strong quill. The microscope, instead of making the image clearer, makes it, on the contrary, vanish, because then the rough parts become prominent. Also on the slab which contains the Pterodactylus medius[H], are seen numerous lines and fibres diverging like a bird's feathers. And on the upper part of the belly is the appearance of a scanty texture of hairs and feathers. The visible marks of two cylinders of the thickness of a quill, made of thin substance and filled with limestone, he would regard as quills if there were clearer marks of their feathers to be seen. As a note upon this von Meyer says, after examining the slabs, that the particles considered by Goldfuss to be hairs and feathers rest upon appearances not only to be seen in the vicinity of Pterodactyles, but which occur upon many other kinds of petrifactions that have nothing in common with the Pterodactyle; and that the roughnesses of the slab have nothing to do with the folds of the wing or the muscles.