Gills deciduous.

I. Ranidae

No tail in the adult state: fore feet with four toes; hind feet with five, or with the rudiment of a sixth.

1. Rana

Skin smooth: hind feet very long, adapted for leaping; more or less palmated: upper jaw with a row of small fine teeth; also a transverse interrupted row on the middle of the palate.

2. Bufo

Body swollen: skin warty; a porous protuberance behind the ears: hind feet of moderate length: jaws without teeth.

II. Salamandridae

Body elongated; tail always present: fore feet with four toes; hind feet with five.

3. Triton

Tail compressed: jaws furnished with numerous small teeth; two longitudinal rows of similar teeth on the palate.