FLYING DRAGONS 
205 
we compare the skeleton of a Pterodactyl (such as the P. specta- 
hilis, now under consideration) with that of a bird, we shall see 
in its fore limbs certain very obvious differences. 
In the first place the arm or wing of a bird has only two, or 
three, bones, instead of four, or five, as here ; secondly the outer 
finger, which corresponds with the human “ little finger ” is 
enormously elongated for the purpose of supporting the thin 
flying membrane. In two ways, however, the skeleton of a 
Pterodactyl does resemble that of a bird, for the bones are more 
or less pneumatic (according to von Zittel) ; and also the position 
of the skull at right angles to the axis bone (on the top of the 
neck vertebrae) is a bird-like arrangement. Again, natural casts 
of the brain cavity prove that the brain was decidedly avian, 
though smaller in proportion to the size of the skull. The orbits 
(for the eye) are very large and surrounded by a ring of small 
sclerotic plates (see Pig. 74). 
In order to give rapid movement to their wings during flight, 
they had powerful muscles in the region of the chest. These 
were attached to a shield-like breast-bone provided with a keel 
— as in birds. But this bird-like feature is only a necessary 
provision to enable them to fly, and does not point to any 
relationship. 
In the year 1873 was discovered, in the lithographic stone of 
Bavaria, at Eichstadt, a very beautiful new form of Pterodactyl. 
This was the Ehamphorhynchus phyllurus. The specimen is in a 
remarkable state of preservation ; for the bones of the skeleton 
are nearly all in position, while those of both wings show very 
perfect impressions of the membranes attached to them. Its 
long tail supported another small leaf-like membrane, which was 
evidently used as a rudder in flight (see Fig. 75). The discovery 
/ 
of this valuable specimen attracted much attention at the time. 
