Anura (ANOURA, THERIOMORPH A, CHELONOBATRACHIA, BATRACHIA)

Order of Amphibia, characterized by a stout body, without tail, with naked skin and well-developed limbs. The vertebræ are procœlous, the eyes have lids, the nostrils are placed far forward, and a tympanic cavity is present in the ear. The vomer, maxillary, and premaxillary bones bear teeth. The tongue is fixed by its anterior end, the hinder being free. Ribs are generally absent. The eggs are surrounded by albumen, which swells in water, where the eggs are spawned. The young hatch as tadpoles, with three pairs of external gills and no limbs. The gills soon give place to internal gills, as in fishes, and an operculum grows back over the gill clefts. The larva beak, is herbivorous, and has a long intes tine. Metamorphosis to the adult carnivorous form takes place by gradual shortening of the intestine, the appearance of limbs, lo of tail and beak and gills. Respiration becomes shifted to the lungs. There are two groups, A glo a and Phaneroglo a .