scaphognathite

Century Dictionary and Cyclopedia

1. n. In Crustacea, an appendage of the second maxilla, apparently representing a combined epipodite and exopodite. In the crawfish it forms a broadly oval plate or scaphoid organ, which continually bales the water out of the respiratory chamber, and so lets fresh water in. See cut at Podophthalmia (C, cd).

Wiktionary

1. n. biology A thin appendage that draws water through the gills of decapods

GNU Webster's 1913

1. n. (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.