Class Amphibia (am-fib’e-ah)
Skin with mucoid secretions and lacking epidermal scales, feathers, or hair, larvae usually aquatic and undergo metamorphosis to the adult; two atrial chambers in the heart; one cervical and one sacral vertebra.
Order Caudata (kaw’dat-ah)
Long tail, two pairs of limbs; lack middle ear. Salamanders, newts.
Order Gvmnophiona (jim”no-fi’o-nah) Elongate, limbless; segmented by annular grooves; specialized for burrowing; tail short and pointed; rudimentary left lung Caecilians.
Order Anura (alvnoor’ah) or Salientia (sS’le-en’tia)
Tailless; elongate hindlimbs modified for jumping and swimming; five to nine presacral vertebrae with transverse processes (except the first); postsacral vertebrae fused into rodlike urostyle; tympanum and larynx well developed. Frogs, toads.