Akademik

lappet
Down-hanging lateral part of carapace [Moore and McCormick, 1969].
Membranous structure, often leaf-like, attached to the distal end of the first segment of the first antenna [Mauchline, 1984].
Ventrally projecting subdivisions of pleura [McLaughlin, 1980].
(Order Mysida):
One of two (anterior and posterior) lobe-like extensions of pleura [Stachowitsch, 1992].

Crustacea glossary. . 2011.