VEETEBRATA 



67 



inclusive, and include man}' species. They are all adapted 

 for aquatic life, and were sometimes formed like the Cetacea ; 

 but others had very long necks, which could extend the 

 head to great depths or reach the surface when the body 

 was sunk. Some of the species reached a length of forty 

 or fifty feet. Their remains have been found in North and 

 South America, Europe, and New Zealand. 



The Pelycosauria includes the 

 families of the Bolosauridse and 

 Clepsydropidse, which were carni- 

 vorous and abundantly provided 

 with teetJi. They have been found 

 in the Permian of South Africa, 

 North America and Europe. 



Two families enter the Orni- 

 THOSAUKiA, viz., the Pteranodon- 

 tidse and the Pterodactylidfe. The 

 last-named family is furnished 

 with teeth, while the first-named 

 includes species which have a 

 toothless beak like that of a bird. 

 The Pterodactylidse range from 

 the Trias to the Cretacic inclusive. 

 The earlier forms had a long tail, 

 and these continued through the 

 Jurassic (Fig. 21). Some of the 

 later forms had an edentulous 

 beak in front of the toothless por- 

 tion. The true Pterodactyles had 

 a much abbreviated tail and a 

 long neck. 



The Ornithosauri were the fly- 

 ing order of reptiles, comparing 

 with the other orders much as 

 bats compare with other orders 

 of Mammalia. 



Fig. iX.—Dimorphodamacronyx 

 Ow. from the English Trias. B, 

 sternum. From Owen. 



