REPTILES 



287 



Box tortoise (Terrapin). From photograph loaned 

 by the American Museum of Natural History. 



thickness. Many of the sea-water turtles are of large size, the 

 leatherback and the green turtle often weighing six hundred to 

 seven hundred pounds each. The flesh of the green turtle and 

 especially the diamond- 

 back terrapin, an animal 

 found in the salt marshes* 

 along our southeastern 

 coast, are highly esteemed 

 as food. Unfortunately 

 for the preservation of the 

 species, these animals are 

 usually taken during the 

 breeding season, when 

 they go to sandy beaches 

 to lay their eggs. 



Characteristics of the Reptilia. — The turtle belongs to the class 

 of vertebrates known as the Reptilia. These animals are charac- 

 terized by having scales developed from the skin. These in the 

 turtle have become bony and are connected with the internal 

 skeleton. Turtles always breathe by means of lungs, differing in 

 this respect from the amphibians. They seem to show their dis- 

 tant relationship to birds in that their eggs are large and are 

 encased in a leathery, limy shell. 



Lizards. — Lizards may be recognized by the long body with 

 four legs of nearly equal size. The body is covered with scales. 

 The animal never lives in water, it is active in habit, and it does not 

 undergo a metamorphosis. Salamanders (commonly called lizards) 

 have a moist skin, and belong to the Amphibia. Lizards are harm- 

 less creatures, the Gila monster of New Mexico and Arizona, a 

 poisonous variety, being the one exception. Lizards are, on the 

 whole, of economic importance to man because they eat insects 

 and include the injurious ones in their dietary. Certain lizards, 

 including injurious ones, notably the chameleon and our common 

 fence lizard, have the power to change the color of the skm. 

 This forms a protective adaptation, for they thus assume the 

 color of their immediate surroundings. The horned toad of our 

 Western states shows another wonderful case of protective adap- 



