Order II. Anura. Tailless Amphibia, which undergo a metamorphosis, breathing by gills in larval state, by lungs in adult state. Examples: toad and frog.
The leopard frog, an amphibian.
Characteristics of Reptilia.—These animals are characterized by having scales developed from the skin. In the turtle they have become bony and are connected with the internal skeleton. Reptiles always breathe by means of lungs, differing in this respect from the amphibians. They show their distant relationship to birds in that their large eggs are incased in a leathery, limy shell.
Classification of Reptiles
Order I. Chelonia (turtles and tortoises). Flattened reptiles with body inclosed in bony case. No teeth or sternum (breastbone). Examples: snapping turtle, box tortoise.
Order II. Lacertilia (lizards). Body covered with scales, usually having two-paired appendages. Breathe by lungs. Examples: fence lizard, horned toad.
Order III. Ophidia (snakes). Body elongated, covered with scales. No limbs present. Examples: garter snake, rattlesnake.
Order IV. Crocodilia. Fresh-water reptiles with elongated body and bony scales on skin. Two-paired limbs. Examples: alligator, crocodile.
