FLYING DRAGONS, OR PTERODACTYLES. 143 



structure of their wings. The true Pterodactyles, as 

 is shown in Fig. 43, are readily characterised by the 

 extreme shortness of the tail ; but in another group, 

 also found in the Lithographic limestones, the tail is 

 as long as that of a lizard. The members of this second 

 group are known as Rhamphorhynchs, and the restora- 

 tion shown in Fig. 44 is taken from a beautiful example 

 found some few years ago, in which the impression of 

 the delicate membrane of the wing is preserved with as 



FIG. 44. Restoration of a Long-tailed Pterodactyle, or Rhamphorhynch. 

 One-seventh natural size. (After Marsh.) 



much sharpness as if made but yesterday. This and 

 other specimens show that while the front edge of 

 the wing was supported by the elongated outer finger 

 the wing extended backwards to embrace the greater 

 part of the hind limb, while the extremity of the tail 

 was furnished with a racquet-shaped expansion of 

 membrane which probably served the purpose of a 

 rudder during flight. Curiously enough, a slab of 

 Lithographic limestone preserved in the museum at 

 Haarlem exhibits a sinuous trail which is believed to 



