40 
FLYING FLAGONS. 
stituting the wings of bats. This wing was mainly supported by the great 
elongation of the bones of the fifth digit or finger of the fore-limb, as shown in 
the accompanying figure of the skeleton, and likewise in the restored representation 
of one of these reptiles. The membrane thus supported seems to have extended 
backwards along the sides of the body to include the upper portions of the legs, 
between which it was extended to embrace the base of the tail in those forms in 
which the latter appendage was 
fully developed. Moreover, in 
the long - tailed species, the 
extremity of the tail itself was 
provided with a racket-shaped 
expansion of membrane, which 
may have served the purpose of 
a rudder in flight. If it be 
asked how the presence of such 
membranes is known, it may be 
answered that in many of the 
specimens of these reptiles en¬ 
tombed in the fine-grained litho¬ 
graphic limestones of Bavaria 
the actual impressions of these 
membranes have been preserved. 
The elongated fifth finger of 
the wing had no claw at the 
extremity, although the three 
middle fingers were thus pro¬ 
vided. With regard to the first 
finger, or the one corresponding 
to the human thumb, this may 
have been represented by the 
small splint - like bone seen 
The creature is lying on its back, with the head bent to the left depending from tile Wl'ist ill the 
side, a indicates the left pubic bone; the liauncli-bone, or ilium, r- i 1 l x nnu 1 • 1 
t . -i ., .. * ., ’ ’ figured skeleton. I he hmd- 
limbs present no special peculiar¬ 
ities, but, as most of the bones of the skeleton were hollow and permeated by air, 
like those of birds, we may infer that the lungs were probably also constructed after 
the avian fashion. The vertebrae of the neck resembled those of living crocodiles 
in having a ball at the hinder end of the body and a cup in front. In general 
conformation the skull was remarkably bird-like, the snout being produced into a 
beak, which in some cases was provided with teeth, while in others, as shown 
in the figure on p. 5, it was toothless, and probably ensheathed during life with 
horn. Bird-like features are likewise shown by the large size of the brain-case, 
of which the component bones were fused together, and also by the union of the 
extremities of the two branches of the lower jaw. 
Pterodactyles flourished during the greater part of the Secondary period, dating 
from the epoch of the Lias, and continuing to the close of the one during which the 
SKELETON OF A ETERODACTYLE. 
