1. They are aquatic or semi-aquatic i.e, amphibious and depend on water to lay eggs.
2. Skin is naked, smooth, moist, rich in glands and highly vascular serving as an efficient res¬piratory organ.
3. Skeleton is bony.
4. Digestive system well developed, protrusible tongue and alimentary canal leads to the cloaca.
5. Respiration may be through lungs, skin and by gills during the larval stage.
6. Heart is 3 chambered, auricle completely divided, but mixing of blood in the ventricle. Examples- Frog, salamander.
