Note: Information is dated. Do not rely on it.Frog. One of the Ranidae, or frogs, a family of tailless amphibians common to widely distributed parts of the world. They have smooth skins, and teeth on the upper jaw, but have no ribs. In North America there is but one genus Rana, of which there are 17 known species. In temperate regions frogs hibernate in the mud of pools or preferably of running water. The eggs are laid in early spring in masses five or six inches in diameter, which are deposited in roadside ditches or still, shallow water. Each female lays from 600 to 1200 eggs.