CHAPTER XII 



REPTILIA (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 



- v> <-=- 



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, sliape 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 



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