Definitions

Cavity on ventral surface of body in which mouth parts are situated; bounded anteriorly by epistome, laterally by free edges of carapace. Within this "frame" lie the mouth parts, which in most Brachyura are covered by operculiform third maxillipeds. [Williams, 1984]
Hollow space on ventral side of body containing mouth parts, in Malacostraca bounded by epistome in front and free edges of carapace on sides. [Moore and McCormick, 1969]
The area on the ventral surface of the carapace in which the mouth parts are situated. Bounded anteriorly by the epistome, laterally by the inner margin of the pterygostomial region and posteriorly by the anterior margin of the first thoracic sternite. [Ingle, 1983]
(Taxon-specific: Class Malacostraca) Area of cephalon containing mouthparts; bounded by epistome anteriorly and free margins of carapace laterally. [McLaughlin, 1980]
(Taxon-specific: Order Decapoda) On underside of head, cavity in which mouthparts (labrum, mandibles, maxillules, maxillae, maxillipeds, labium) are located. [Stachowitsch, 1992]
(Taxon-specific: Subclass Branchiura) In front of mouth, chamber formed by lip-like extensions of proboscis margins. Contains mandibles. [Stachowitsch, 1992]
(Taxon-specific: Subclass Copepoda) In parasitic copepod, term applied to space formed around mouth by prolonged upper lip (labrum) and lower lip (labium). (See also mouth cone). [Stachowitsch, 1992]