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ORDERS OF REPTILES— INTRODUCTION 
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. 
ORDER. PRONUNCIATION. GROUPS INCLUDED. 
EXAMPLES. 
Crocodilia 
Chelonia. . 
Lacertilia 
Ophidia 
Croc-o-dil'i-a 
Ke-lo'ni-a 
La-ser-tiV i-a 
O-fid'i-a. 
Gavials, Crocodiles, Alligators. . . .Florida Crocodile, Alligator. 
\ Tortoises, Terrapins and Sea- 
( Turtles. 
. Iguanas, Slow-W orms, Skinks . 
j Colubrine Snakes, Rattlesnakes, 
( Harlequin Snakes. 
Box Tortoise, Painted Ter- 
rapin, Hawksbill Turtle. 
Marine Iguana, Glass “ Snake,” 
Blue-Tailed Lizard. 
Anaconda, Timber Rattle- 
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 Berlin Museum are the well-preserved 
fossil remains of a bird called the Ar-chae-op'ter- 
yx, which had a long, lizard-like tail fully cov- 
ered with feathers, and lizard-like teeth in its 
beak. In 1873, Professor Marsh discovered in 
tire chalk-beds of western Kansas, a low-formed, 
penguin-like 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 crocodilians 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 live. 
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 alive. 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 
