physostomi

from The Century Dictionary.

• noun An order of teleost fishes established by J. Müller in 1845, containing those whose air-bladder, when present, is connected with the alimentary canal by an air-duct, the bladder thus having an outlet or mouth: contrasted with Physoclisti.

from the GNU version of the Collaborative International Dictionary of English.

• noun plural (Zoöl.) 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.