AMPHIBIA
Description: "Double life", or life in water and on land, being tetrapods (4 limbs) that facilitate moving about on land. Skin is thin, soft, glandular and magid (lack scales except in the caecilians). Both gill and lung breathers, usually gills in the larval stage, replaced by lungs in the adult; cutaneous respiration in many three-chambered heart with two atria and one ventricle, unable to regulate body temperature.