I. The tongue is attached by its central pedicle only, is free all round, ends in a soft knob and can be shot out to a considerable distance.
With 5 toes: Spelerpes, p. [104].
With 4 toes: Manculus, p. [106].
II. The tongue is attached along the middle line and cannot be protruded out of the mouth.
Jaws with numerous small teeth.
With 5 toes: Plethodon, p. [106].
With 4 toes: Batrachoseps.
Maxillary and mandibular teeth few in number but very large.
With 5 toes: Autodax, p. [107].
Spelerpes.–Except in a few species the limbs are well developed and possess 4 fingers and 5 toes, which are either free or webbed. But in the Colombian S. parvipes, still more in S. lineolus of Orizaba and S. uniformis of Costa Rica the limbs and digits are reduced to mere vestiges, and are practically without function, the body, with the extremely long tail, having assumed a wormlike shape. The young of many, if not all, species have a pair of short balancers below each nostril; in the adult these organs are reduced to little swellings or lost completely. Several species are lungless, see p. [46].