12 CROCODILES AND ALLIGATORS 



General Characters of Crocodilians. — A crocodilian is 

 a lizard-like reptile, of very large size, with short, thick legs, 

 a long tail and the most highly developed vascular system 

 to be found among reptiles. Its back and neck are pro- 

 tected by powerful armor consisting of rough, lozenge-shaped 

 plates of solid bone set in a very thick and tough skin, and 

 arranged in rows, both lengthwise and crosswise. 



Both the tail, the abdomen and throat are covered by 

 a regular arrangement of tough scales. The whole animal is 

 covered by a thin, translucent epidermis which is impervious 

 to water. The tail is long, flattened vertically and fringed 

 along the top with a row of lofty, saw-toothed scales of great 

 use in swimming. 



The head is a mass of well-nigh solid bone, overlaid by 

 the same thin layer of scaly epidermis which covers the 

 body, of the thinness of writing-paper. The nostrils are 

 placed far forward, near the end of the snout. The jaws pos- 

 sess great strength, and are armed with rows of sharp-pointed, 

 conical teeth, which are shed when worn out, and renewed. 



The tongue is not free, but is firmly attached to the bot- 

 tom of the mouth. Its color never is red, but usually is yel- 

 lowish-white, and sometimes pinkish. The iris of the eye is 

 dark green, and the pupil is very narrow, and vertical. The 

 eyelids are movable, and the ear-opening closes tightly by a 

 flap of skin controlled by voluntary muscles. 



Most saurians are voiceless or nearly so; but the alligator 

 emits a very deep bellow, or roar, which in animals over 10 

 feet in length is much lower on the scale than any fog-horn. 



'The difference between a crocodile and an alligator" (a 



