NECROPHAGA AND THEIR ALLIES. 
123 
very narrow, composed of a thin neck and broader 
plate, fringed with very long closely- planted hairs; 
their metathorax is very large ; their abdomen com- 
posed of six or 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, sharp at the point, and milled on their 
outer edge ; and the maxillae have their stem much 
developed and terminated in two lobes. In some of 
the genera the posterior coxae are very much en- 
larged. 
This family has been elaborately monographed by 
the Rev. A. Matthews (London, 1872), and also, but 
far less completely, by Dr. Gillmeister (Nuremburg, 
1845) ; the drawings of the minute species, in both 
these works, are models of what drawings of insects 
should be. 
Our species occur under bark, in wet leaves, 
marshy places, refuse heaps, &c. ; aud Trichopteryx 
atomaria (one of the largest), a black, flattened, 
square little insect, may be seen running actively if 
garden stulf be shaken over brown paper, being often 
accompanied by tho smaller, narrower, more convex, 
and shining Ptenidium apicale (Plate XVI., Fig. 2). 
Nossidium pilosellum, the largest of the family, 
convex, and set with evident hairs, is rare, but 
occurs in profusion when found, on the surface of 
decomposing wood ; and the species of Ptinella, 
elongate, yellow, Hat, with their black folded wings 
often showing through their elytra, live under bark. 
The CoRYLOPHiDAi comprise several minute insects, 
