; class Amphibia)
An extant order of amphibians, now confined to the tropics and subtropics, that have become adapted to a burrowing life and look like large earthworms. They are the only living amphibians some species of which have retained scales, although the scales are vestigial and hidden in folds of the skin. They have no limbs or limb girdles, eyes that are rudimentary, vestigial hearing apparatus, a sensory feeler beneath the eye, no gills or gill slits in the adults, and a tail that is small or absent. Fertilization is internal, as a cloacal copulatory organ is developed in the male. There are three families: Caecilidae; Ichthyophiidae; and Typhlonectidae.
Subjects: Zoology and Animal Sciences.