Zool. [mod. f. Gr. ἀμφί both + -πνευστ-ος breathing, f. πνέ(υ)-ειν to breathe. Pl. -s, or collectively amphipneusta; first applied by Merrem 1790–1820.] An animal that breathes both by lungs and by gills; a name given by some to the lowest order of the Amphibious animals, including the Proteus and Siren, which retain their gills all their lives.
1841. Penny Cycl., XIX. 408/2, quoting J. A. Gray (1831). In the second section (Amphipneusta) are placed the Protei.
1847. in Craig.
