632 BIOLOGY. 



teeth almost like the Crocodile. Ichthyosaurus, Plesio- 

 saurus. 



Fam. 11. Typical Reptiles, Salmon-like Geckos. 



Climbing feet, or retractile claws as in the Cats, and 

 perpendicular laminae or plates under the soles, by means 

 of which they cling to walls. They usually dwell in 

 houses and catch beetles Chamaeleo, Gecko. 



Fam. 12. Ornithoid Reptilia, Pike-like Dragons. 



Body short and bird-like, with very long neck and a 

 long digit, unto which an alary membrane has probably 

 been attached. 



Here belong plainly the fossilized species of a single 

 genus known by the name of Pterodactylus. They have 

 been hitherto discovered in different parts of Europe, and 

 probably flew about, like the Bats, by night. 



Order 5. Censorial Reptiles. 



3548. Teeth wedged into the jaws, toes regular. 

 Fam.\. Thricozooid Reptilia, Shark-like Crocodiles. 

 Feet and toes of equal length, with swimming webs 



between them. 



The Crocodiles must be without doubt regarded as the 

 most perfect Reptilia, on account of their notched teeth 

 and regular feet. In many respects they remind us, like 

 the Sharks do among Fishes, of the Thricozoa. 



Twelfth Class. 

 Neurozoa, Otozoa Aves. 



3549. In these animals it is again shown in a striking 

 manner, that the characteristic organ is the principle of 

 classification. Without recourse being had to the varied 

 structure of the head, especially of the beak, the division 

 of Birds would not be possible, although the feet fre- 

 quently yield good characters. 



3550. The development of the young makes an 

 essential distinction upon a large scale, since one great 

 body of Birds must be fed as nestlings, whilst the other, 

 when scarcely emerged from the egg, runs about and seeks 



