516 ZOOLOGY. 



Still nearer the birds was the Compsognatlms ; it was 

 only two thirds of a meter (2 feet) long, with a light head, 

 toothed jaws, and a very long, slender neck ; the hind limbs 

 were very large and disposed as in birds, the femur being 

 shorter than the tibia ; moreover, the fore legs were very 

 small. "It is impossible," says Huxley, "to look at the 

 conformation of this strange reptile and to doubt that it 

 hopped or walked, in an erect or semi-erect position, after 

 the manner of a bird, to which its long neck, slight head, 

 and small anterior limbs must have given it an extraordi- 

 nary resemblance." The so-called bird tracks of the Triassic 

 rocks of the valley of the Connecticut were all reptilian 

 footprints, and without doubt made by Dinosaurs with the 

 above-mentioned affinities to the birds. These bird-like, 

 colossal lizards appeared in the Jura-Trias Period, and be- 

 came extinct in late Cretaceous times. 



Order 11. Pterosauria. The forms of this order, rep- 

 resented by the Pterodactyles, would lead one to infer that the 

 group was still more bird-like than the Dinosaurs, and See- 

 ley has shown that they have as many and important points 

 of similarity to that class as the preceding group. They are 

 a sort of reptilian bats, forming links between reptiles and 

 flying birds, as the Dinosaurs connect with the ostriches, 

 and it is in the hand and foot, which in birds are the most 

 characteristically ornithic, that they resemble the ornithic 

 type. They also approach birds in their long heads and 

 necks, the jaws with or without teeth, the short tail, in the 

 skull which is more rounded and bird-like than in other 

 reptiles, with large orbits, as also in the form of the brain ; 

 while the jaws were probably, in part at least, encased in 

 horny beaks. The shoulder girdle was bird-like, and the 

 sternum was keeled, but the pelvis and limbs were like 

 those of lizards, while the fore-feet were much larger than 

 the hinder ones, and the ulnar finger was enormously 

 long and probably supported a broad membrane, connecting 

 the fore and hind limbs, as in bats; moreover, the limb 

 bones were hollow, and air-cells were present, so that 

 these winged lizards could fly like birds or bats. The jaws 

 of the Pterosaurs were completely toothed ; those of the 



