SKELETON GENERALLY 



131 



two. The J omit the one that floats loosely back over 

 the side, called the Comcoid. While nearly all rep- 

 tiles have a collar-bone (or bones) the flying Ptero- 

 dactyl forms had none. 



In the thigh-junction, the Eeptiles have peculiari- 

 ties which the anatomist easily recognizes. In such 



Fig. 60. — Wall gecko (Platydactylus muralis). A, foot of gecko, show- 

 ing suction slats by means of which it adheres to perpendicular 

 surfaces. 



reptiles as walked on two legs these bones have quite 

 a birdlike arrant^ement. The Dinosaur and bird 

 have long projecting bones behind to support them 

 in an upright posture. 



The IwiBS have been noted as many and long — 



