Modified rostrum of brachyuran decapods which bears downward projection process between antennules that unites with epistome [Moore and McCormick, 1969].
(Order Anostraca):
Clypeus [Stachowitsch, 1992].
(Order Decapoda):
In carapace of crab-like (brachyuran) decapod, modified rostrum which bears downwardly directed process united with ventral epistome [Stachowitsch, 1992].
(Subclass Copepoda):
In parasitic copepod, plate-like structure at anterior end of head; formed by fusion of frontal margin with bases of antennules. Bears pair of suckers (lunules) [Stachowitsch, 1992].
(Infraorder Brachyura):
Modified rostrum with downward projecting process united with epistome [McLaughlin, 1980].
(Order Euphausiacea):
Somewhat extended anterior margin of carapace. (short and triangular, truncate) [Stachowitsch, 1992].
Crustacea glossary. Natural History Museum of Los Angeles County. 2011.