ABSTRACT
Pronotum broader than head, usually much wider than long; anterior border broadly emarginate, lateral borders usually evenly arcuate, slightly to moderately divergent or constricted posteriorly, posterior border evenly arcuate to slightly sinuate with a very narrow transverse ridge just beneath it; all borders very narrowly margined, surface usually smooth, sometimes with bumps, depressions or grooves, finely to deeply punctate, often with a short line of setiferous punctures near outer anterior edges and /or just past middle (systematic punctures, Figs. 19.13-21.13); notopleural suture absent; prosternum short to moderate, with an intercoxal process extending posteriorly, lateral margins with a narrow glabrous border, procoxal cavities usually open behind or rarely closed (Hydrochus). Scutellum triangular, of variable size, usually distinct (except in Georissinae). Mesosternum large, depressed, somewhat keeled, plate-like or with a hood-like process (with a highly variable central keel, anterior projection or flattened area); mesepisternum reaching coxal cavities; mesocoxal cavities open behind. Metasternum large, variable, may be keeled; metepisternum reaching coxal cavities; metacoxal cavities very large.
