49a (1). Form beetle-like; antennae usually not clubbed, but if so then club segments are not lamellate (= with leaf- or plate-like segments); 1st visible abdominal sternite not normally interrupted by the hind coxal cavities; outer lobe or galea of maxillae not a segmented process (= palpiform), maxillary palpi much shorter than antennae; hind tarsi with at least as many segments as front and middle tarsi; elytra (= the thickened front wings) short, exposing much of abdomen (Fig. A)......................................................................…………….......Staphylinidae.....50

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49b. Elytra covering most of abdomen, not shortened............…….............................................................. [not parasitic on synanthropic Diptera]