CHAPTER XII 

 REPTILfA (REPTILES) 



THIS class is divided into four orders which have such 

 marked differences of external form that there is no diffi- 

 culty in distinguishing them. These orders are represented 

 by Lizards, Snakes, Turtles, and Alligators. Of these, only 

 the forms of lizards and alligators have similar propor- 

 tions, .but there is a marked difference in their size, 

 lizards being, in general, the smallest, and alligators the 

 largest of the reptiles. 



Comparison of Lizards and Salamanders. To make clear 

 the difference between reptiles and batrachians, it will be 

 well to compare the orders in the two classes which re- 

 semble each other in size and shape ; namely, lizards and 



FIG. 263. A SALAMANDER. 



FIG. 264. A LIZARD. 



salamanders (Figs. 263 and 264). State in a tabular form 

 their differences in skin, toe, manner of breathing, develop- 

 ment from egg, shape of tail, habitat, habits. Each has 

 an elongated body, two pairs of limbs, and a long tail, yet 

 they are easily distinguished. Are the differences sug- 

 gested above valid for the other batrachians (frogs) and 

 other reptiles (e.g. turtles) ? Trace the same differences 



