Opening through which water passes to gills [McLaughlin, 1980].
Openings through which water passes to gills, in brachyuran crabs generally located in front of bases of chelipeds [Moore and McCormick, 1969].
Openings through which water passes to gills. In brachyuran crabs, usually opening behind pterygostomian regions and in front of chelipeds except in certain Oxystomata in which they open at anterolateral angles of palate or endostome [Williams, 1984].
Crustacea glossary. Natural History Museum of Los Angeles County. 2011.