lophobranchii

from The Century Dictionary.

• An order of teleost fishes having the branchial skeleton imperfect, the superior and basal branchihyals and pharyngeals wanting, and the gills not lamellar, but developed as loop-like or tuft-like lobes, whence the name.

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

• noun plural (Zoöl.) An order of teleostean fishes, having the gills arranged in tufts on the branchial arches, as the Hippocampus and pipefishes.