gnathostegite

Century Dictionary and Cyclopedia

1. n. In Crustacea, a lamellar expansion of the ischiopodite and meropodite of the external maxilliped or third thoracic limb, which with its fellow covers the other mouth-parts. It may be terminated by a small jointed endognathal palp.

Wiktionary

1. n. zoology, rare One of a pair of broad plates, developed from the outer maxillipeds of crabs, and forming a cover for the other organs in the mouth.

GNU Webster's 1913

1. n. (Zoöl.) One of a pair of broad plates, developed from the outer maxillipeds of crabs, and forming a cover for the other mouth organs.