VERTEBRATA. 



253 



striction, or neck, behind the head, two or more fangs and 

 few teeth, small eyes with vertical pupil, and short, thick 



FIG. 150. i. Rock Snake, (Python molurus^ 2. Spectacled Snake, (Cobra de Cap- 

 fllo. 3. Boa Constrictor. 



tail. In the harmless Snakes the head blends with the 

 neck, and is covered with plates, (Fig. 151,) the teeth 

 are numerous in both jaws, the pupil is round, and the 

 tail tapering. 



2.) Lacertilia, comprising Chameleons, Blindworms, 

 and Lizards, are distinguished from the other orders by 

 possessing clavicles, and having teeth not lodged in sock- 

 ets, as in the Crocodiles. They are often like Snakes 

 with four limbs, each having five digits. Some have no 



exoskeleton, but it is generally present in the shape of 



22 



