184 MANUAL OF NATUEAL HISTORY. 



23. Family. — Flat Bark-Beetles (Cucujidae), An- 

 tennae rather long, moniliform, slightly thick- 

 ened at tip or distinctly clavate ; palpi short, 

 filiform ; mandibles large, exserted, bifid at 

 tip ; labrum rounded ; head large, exserted ; 

 body oblong, flat. Chiefly found beneath the 

 bark of trees. 



24 Family. — Skin-Beetles (Dermestidae). Antennae 

 short, rather abruptly clavate ; club 3 — 

 4-jointed ; palpi very short ; mandibles short, 

 thick, toothed at tip ; labrum short, membra- 

 nous at tip ; body convex, oval, rounded at 

 each end, clothed with scales or pile ; legs 

 contractile. Counterfeit death. Found in old 

 skins, furs, and dried carcasses. 



25. Family. — Nocturnal Wood-Beetles (Paussidae). 

 Antennae very large, of two or more joints ; 

 irregular ; palpi much developed, unequal ; 

 head small, generally narrowed behind into 

 a neck ; body oblong, quadrate, depressed ; 

 elytra broader than thorax ; legs short, 

 strong, compressed. Nocturnal, wood-eating. 



Y. SUB-ORDER.— Rove-Beetles (Brachelytra). 



Mandibles strong, seldom exserted ; palpi gene- 

 rally filiform or subulate, rarely clavate ; maxillary 

 palpi 4-jointed, labial 3-jointed, their last joint some- 

 times minute or obsolete ; maxillae with the tip 

 often bifid ; outer lobe palpiform ; body very long, 

 narrow, with two vesicles at tip ; elytra consider- 

 ably abbreviated, rarely covering half the abdomen ; 



