The Collaborative International Dictionary of English v.0.48:

Lophobranchii \Loph`o*bran"chi*i\, n. pl. [NL., fr. Gr. lo`fos a
   crest or tuft + bra`gchion gill.] (Zool.)
   An order of teleostean fishes, having the gills arranged in
   tufts on the branchial arches, as the Hippocampus and
   pipefishes.
   [1913 Webster]