VON MEYER ON PTERODACTYLUS. 73 



were flying animals. This singular similarity to birds which have 

 the most powerful flight is united with characters which more deci- 

 sively connect the Pterodactyles with the Saurians, as appears in the 

 structure of the skull, of the lower jaw, of the pelvis, in the teeth 

 inserted in separate alveoli, as well as in the existence of abdominal 

 ribs. The Pterodactyles thus form a long-extinct, independent class 

 of Saurians, which had the power of flight, and also perhaps of 

 moving on the surface of the water, yet not in the same manner as 

 the tortoises, whose hand is differently constructed, and whose bones 

 are not hollow but of a compact structure, as is also true of those birds 

 which, like the Apteryx and Dinornis, were not adapted for flight. 

 I therefore also believe that the Pterodactyles were not clothed with 

 feathers like birds, nor yet with hair like the mammalia, but had a 

 naked skin. 



The name Pterodactylus — wing-finger — was well chosen by Cuvier. 

 They are in reality distinguished from all other animals by this, that 

 their finger gives them the power of flight ; and indeed only one 

 finger, the ear or little finger, as it is named from its small size in 

 the hand of other creatures. In the Pterodactylus it acquires con- 

 siderable length. The bats, which likewise are able to fly, can do 

 so principally by means of their hand, in which four fingers are de- 

 veloped into instruments of flight, the thumb alone being excepted 

 from this change. Besides, in the bat the lengthening of the hand 

 takes place in the metacarpal bones, which in the Pterodactylus are 

 not longer than ordinary. In the birds the hand is even more spa- 

 ringly developed, and this is especially true of the fingers, which are 

 never more than three in number even in young birds. In them the 

 power of flight depends on the proportionate length of the fore-arm 

 and upper-arm, and properly they are only enabled to fly by means 

 of the wing-feathers, whose place is supplied in the Pterodactylus 

 and bat by the fingers and connecting membrane. 



A sufficient number of Pterodactyles are now known to induce us 

 to attempt a plan for their classification. The wing-finger in these 

 animals was always believed to consist of four phalanges. I was 

 therefore surprised, in looking over the old collection of Lavater at 

 Zurich, to find pieces of lithographic slate, with remains of a Ptero- 

 dactylus, in which the wing-finger was composed of only two pha- 

 langes, like the long finger in birds, which this species likewise re- 

 sembled in the wing-finger being articulated to a metacarpus formed 

 of two strong bones ; the hand otherwise being formed as in other 

 Pterodactyles. Another peculiarity of certain Pterodactyles is, that 

 the anterior extremity of the jaws was prolonged into a toothless 

 point. Although this peculiarity seems to separate these Pterodac- 

 tyles very widely from all others, yet Ft. longicaudus shows that it 

 had no influence on the number of phalanges in the finger, which in 

 this species always consists of four. On the other hand, the Pt. 

 Gemmingi proves that the edentulous prolongation of the jaw was 

 connected with a tail of remarkable length, with the anchylosing of 

 the scapula and clavicle, and perhaps with the absence of an osseous 



