dipnoi
Dip"no*i, n. pl. Etym: [NL., fr. Gr. (Zoöl.) Defn: A group of ganoid fishes, including the living genera Ceratodus and Lepidosiren, which present the closest approximation to the Amphibia. The air bladder acts as a lung, and the nostrils open inside the mouth. See Ceratodus, and Illustration in Appendix.