scaphognathite

from The Century Dictionary.

• noun In Crustacea, an appendage of the second maxilla, apparently representing a combined epipodite and exopodite.

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

• noun (Zoöl.) A thin leafike appendage (the exopodite) of the second maxilla of decapod crustaceans. It serves as a pumping organ to draw the water through the gill cavity.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun biology A thin appendage that draws water through the gills of decapods