Cutaneous respiration
The skin of amphibians is a major site of respiration in all species for which measurements are available. Cutaneous respiration is the sole respiratory mode of lungless salamanders (family Plethodontidae) which lack lungs entirely yet constitute the largest family of salamanders. Cutaneous respiration in frogs and other amphibians may be the primary respiratory mode during colder temperatures.
Myobatrachidae
These frogs lack adhesive toe discs found in the tree frogs. The family is broken into subfamilies based mainly upon their egg-laying habits. Those of the subfamily Limnodynastinae lay foam nests. The female creates foam by agitating a chemical on her skin with her hands. The foam may float on top of water, or be on land. The subfamily Rheobatrachinae contains the two species of gastric-brooding frogs, and the rest are within the subfamily Myobatrachinae.