566 FOSSIL SAURIAN S ; PTERODACTYLUS. 



possessing teeth in one of the jaws. They are found in the 

 warm parts of both Hemispheres, where they live, like the Am- 

 phisbsenas, in the ground or under stones, often burying them- 

 selves to a depth of three or four feet during the rainy season. 

 They feed principally upon insects and worms. 



504. Besides the fossil Reptiles already referred to, some of 

 which establish, in such a remarkable manner, the connexion be- 

 tween this class and the other Vertebrata, we have still to refer to 

 one of the most singular groups of Reptiles yet discovered, either 

 in the recent state, or amongst the ruins of the ancient world. 

 The remains of the Pterodactylus (Fig. 307), the chief peculiarity 

 in whose structure has been already noticed ( 468), are found in 

 the lias and oolite formations ; mingled with the remains of large 

 insects, such as Dragon-flies and Beetles. There can be no doubt 

 that they were adapted to lead the life of the Bats and Swallows 

 of the present day ; restraining the multiplication of the Insect 

 tribes, at a period when neither Birds nor Bats existed. Some 

 of the larger species may not improbably have been partly 

 aquatic in their habits, and may have fed on fish. From the 

 size and form of the posterior extremities, the Pterodactylus 

 seems to have been able to walk and perch upon them, after the 

 manner of Birds ; and with the anterior and posterior combined, 

 it could probably walk and climb on rocks and cliffs, like Bats 

 and Lizards. Several species have been already found, and more 

 probably remain to be discovered ; their size varied from that of 

 a Snipe to that of a Cormorant. One of these was remarkable 

 for the enormous length of its head ; in all of them the neck was 

 very long, and thus enabled the head to make a sudden dart 

 upon the prey. 



ORDER III. OPHIDIA. 



505. THE division of the class of Reptiles which includes 

 the Serpent tribes, is one which is almost universally regarded 

 with feelings of horror and aversion. These doubtless originate 



