The Collaborative International Dictionary of English v.0.48:

Physostomi \Phy*sos"to*mi\ (f[i^]*s[o^]s"t[-o]*m[imac]), prop.
   n. pl. [NL., fr. Gr. fy^sa a bellows + sto`ma mouth.] (Zool.)
   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.
   [1913 Webster]