- An unpaired dorsal unit of the cephalon bearing the labrum medially and the mandibular fossae laterally. The fossae articulate with the dorsal condyle of the mandibles [Wilson, 1989].Part of head carrying labrum; plate on anterior medial part of head formed by fusion of basal segments of antennae (e.g., Branchipus, also Hexapoda) [Moore and McCormick, 1969].(Order Anostraca):Part of cephalon carrying labrum; plate anteromedially on head formed by fusion of basal segments of antennae [McLaughlin, 1980].(Order Anostraca):Plate-like structure fromed by medial fusion of bases of antennae. (with/without digiform process). (Syn. frontal plate) [Stachowitsch, 1992].(Order Tanaidacea):On underside of head, plate-like structure bearing upper lip (labrum). Separated from labrum by suture [Stachowitsch, 1992].(Order Isopoda):In most (but not all) isopods the labrum consists of two pieces; the anteriormost (proximal) piece is referred to as the clypeus, the posteriormost (distal) piece as the labrum proper [Wetzer et al. 1997].():Nomenclature of isopod cephalon (A). Examples of isopod mouth appendages: Idoteidae (B, C, F, H); Cirolanidae (D, E, G, I). [Wetzer et al. 1997](Order Isopoda):(Order Isopoda):Platelike structure of cephalon, anterior to upper lip or labrum, sometimes fused with frontal lamina [Kensley and Schotte, 1989].()Schematic representation of an isopod illustrating morphological terms. [Kensley and Schotte, 1989]
Crustacea glossary. Natural History Museum of Los Angeles County. 2011.