314 



OKDEKS OF EEPTILES— INTEODUCTION 



of living Reptiles; the seven that are extinct can 

 be studied elsewhere by those who become spe- 

 cially interested in this subject. 



The Grand Divisions of Living Reptiles. — 

 There are, all told, eleven Orders of the 

 Class Reptilia; but seven of them are extinct, 

 and for the present these will be- left out of 

 consideration. The four Orders of living rep- 

 tiles are made up as shown in the following 

 synopsis: 



wide range of variation, beginning with the 

 clumsy-flippered harp-turtle, passing the gila 

 monster, the swift-footed monitor, the kangaroo- 

 like collared lizard (of Arizona), the gliding ser- 

 pents, and ending with the flying dragon. 



In their food habits, the range of the world's 

 reptiles is infinitely great, embracing fruit, vege- 

 tables, herbage, and all forms of flesh, living and 

 dead. Oddly enough, however, no modern rep- 

 tile has been provided with molar teeth for the 



THE ORDERS OF LIVING REPTILES. 



PRONUNCIATION. 



GROUPS INCLUDED. 



EXAMPLES. 



Crocodilia Croc-o-dil'i-a Gavials, Crocodiles, Alligators Florida Crocodile, Alligator, 



Chblonia Ke-lo'ni-a. . 



( Tortoises, Terrapins and Sea- j^ Box Tortoise, Painted Ter- 

 I Turtles. 



( rapin, Hawksbill Turtle. 



_ ,.„. T cji iir OT • 1 i Marine Iguana, Glass " Snake," 



Lacertilia La-ser-M'i-a Iguanas, Slow-Worms, bkmks . j Blue-Tailed Lizard. 



/-N r>£jt- ( Colubrine Snakes, Rattlesnakes, ) Anaconda, Timber Rattle- 



Ophidia U-fid i-a | Harlequin Snakes. 1 snake, Coral Snake. 



General Characters of Reptiles. — Chiefly 

 through certain extinct species, the reptiles lead 

 so directly into the birds that the two Classes 

 overlap each other. 



In the Berhn Museum are the well-preserved 

 fossil remains of a bird called the Ar-chae-op'ter- 

 yx, which had a long, lizard-hke tail fully cov- 

 ered with feathers, and lizard-like teeth in its 

 beak. In 1873, Professor Marsh discovered in 

 the chalk-beds of western Kansas, a low-formed, 

 penguin-Uke bird, called the Hes-per-or'nis, also 

 provided with teeth. 



All reptiles are cold-blooded animals, and 

 breathe air by means of lungs. Because of the 

 low temperature of their blood, and their slow 

 heart-action, many of them are able to remain 

 under water for quite lengthy periods — of min- 

 utes, not hours. Some turtles and terrapins 

 become so thoroughly dormant at the approach 

 of winter that the vital organs actually suspend 

 their functions, for a period of from one to three 

 months. It is then that these creatures bury 

 themselves in the mud at the bottom of ponds, 

 and so pass the winter months. 



The majority of reptiles are covered with scales, 

 or armor of solid bone, and are provided either 

 with teeth for conflict and offence, or with armor 

 for defence. Their means of locomotion show a 



mastication of food. The saurians, lizards and 

 serpents have teeth for seizing and holding their 

 living prey. The turtles, however, are quite 

 toothless, and in place of teeth their horny jaws 

 have sharp, cutting edges for clipping up their 

 food into pieces small enough to be swallowed 

 without mastication. 



The teeth of serpents and crocodiHans gen- 

 erally are perpetually renewed, as fast as old 

 teeth are worn out, and disappear. By reason 

 of this, the lives of these reptiles are indefinitely 

 prolonged, and it is believed that some of them 

 continue to grow almost as long as they five. 



The great majority of reptiles reproduce by 

 laying eggs, which are hatched either by the heat 

 of the sun, or by the fermentation of muck- 

 heaps. Many species of serpents hatch their 

 eggs in their own bodies, and bring forth their 

 young aUve. Such species are called vivip'arous. 

 Those which lay eggs are called o'viparous. 



Some reptiles, notably the crocodiles and 

 tortoises, continue to grow almost as long as they 

 live. Doubtless this is also true of some large 

 species of serpents, such as the great constrictors 

 of India and South America. 



Distribution. — Reptiles reach their maximum 

 development in the tropics, and the subtropics, 

 between the isothermals of 32° F. North and 



