THE PSEUDOTRIMERA. 233 



posed of a thin neck and broader plate, fringed with 

 very long closely-planted hairs; their metathorax is 

 very large; their abdomen composed of from five to 

 seven segments, of which the first or the last is usually 

 the largest ; and their tarsi are composed of three 

 joints, the apical being very long, and having a long 

 hair between its claws. The labrum is usually large 

 and transverse ; the mandibles short, arched, and sharp 

 at the point; and the maxillae have their stem much 

 developed and terminated in two lobes. In some of the 

 genera the posterior coxae are very much enlarged. 



This family has been elaborately monographed by Dr. 

 Gillmeister (Nuremberg, 1845), whose drawings of its 

 minute species, admirably engraved by Sturm, are mo- 

 dels of what figures of insects should be. 



Our species occur under bark, in wet leaves, marshy 

 places, refuse heaps, etc. ; and Trichopteryx atomaria 

 (one of the largest), a black, flattened, square little in- 

 sect, may be seen running actively if garden stuff be 

 shaken over brown paper, being often accompanied by 

 the smaller, narrower, more convex, and shining Pteni- 

 dium apicale (Plate XVI, Fig. 2). 



Nossidium pilosellum, the largest of the family, convex, 

 and set with evident hairs, is rare, but occurs in profu- 

 sion when found, on the surface of decomposing wood ; 

 and the species of Ptinella y elongate, yellow, flat, with 

 their black folded wings showing through their elytra, 

 live under bark. 



The LATHRIDIAD^E have clavate antennae inserted a 

 little before the eyes, the club being three-jointed in 

 Lathridius and Corticaria, and two-jointed in Holopa- 

 ramecus ; the latter is also noteworthy on account of 

 the variation of the number of joints from nine to 



