OSDMB OF LIZARDS. 501 



-arches of the vertebral coliimn interlocked more extensively 

 "than in other reptiles except the snakes. They swam rapidly 

 through the water by rapid undulations of their bodies aided 

 by the paddles. The skull was not so strong, though as 

 -light as that of the serpents. "While the jaws were longer, the 

 ^ape was not so extensive as in serpents of the higher groups, 

 for the OS quadratum, the suspensor of the lower jaw, though 

 equally movable and fastened to widely spread supports, was 

 much shorter than in them. But there was a remarkable 

 -arrangement to obviate any inconvenience arising from these 

 points. While the branches of the under jaw had no natural 

 •connection, and possessed independent motion, as in all ser- 

 jpents, they had the additional peculiarity, not known else- 

 whei"e among Vertebrates (except with snakes), of a movable 

 -articulation a little behind the middle of each. Its direction 

 being oblique, the flexure was outwards and a little down- 

 wards, greatly expanding the width of the space between 

 "them, and allowing their tips to close a little. A loose flexi- 

 ble pouch-like throat could then receive the entire prey 

 iswallowed between the branches of the jaw ; the necessity of 

 holding it long in the teeth, or of passing it between the 

 short quadrate bones could not exist. Of cotirse the glottis 

 and tongue would be forwards." The order became extinct 

 before the Tertiary Period. 



Order 3. Lacertilia. —The existing lizards or Saurians are 

 the survivors or descendants of a multitude of forms, many 

 'Colossal in size, which characterized the Permian and Meso- 

 zoic periods ; while the extinct forms of reptiles were in 

 many cases synthetic types, with affinities to fishes, Am- 

 phibians, and even birds. The group as now existing is well 

 circumscribed. 



Most lizards have cylindrical bodies, usually covered with 

 small overlapping scales, with a long, slender tail, and general- 

 ly two pairs of feet, the toes long and slender, and ending in 

 claws. They run with great rapidity, and are active, agile 

 •creatures, adorned with bright metallic colors, in some cases 

 green or brown, simulating the tints of the vegetation or 

 soil on which they live ; some are capable of changing their 

 ■color at will, as in the chameleon and Anolis ; this is due to 



