Source : Webster's Revised Unabridged Dictionary (1913)

Physostomi \Phy*sos"to*mi\, n. pl. [NL., fr. Gr. ? a bellows + ?
   mouth.] (Zo["o]l.)
   An order of fishes in which the air bladder is provided with
   a duct, and the ventral fins, when present, are abdominal. It
   includes the salmons, herrings, carps, catfishes, and others.