Page:Jardine Naturalist's library Entomology.djvu/301

Rh, was established by Kirby for the reception of the Linnean genus Phryganea, previously associated with the Neuroptera, but to which its characters by no means conform. Instead of being reticulated, the neuration of the wings is simply branching, the nervures disposed in a manner bearing some resemblance to that observed among the Lepidoptera. The upper pair are mostly hairy, (hence the name from θριξ, τριχος, hair,) the under pair ample and folded. The organs of the mouth are in a great measure obsolete, the mandibles being either entirely wanting or very imperfect. Such is likewise the case with the maxillæ and labium, but the palpi are developed. The abdomen is never furnished with terminal setæ, and the tibiæ of many are armed with two pair of spurs, as in many kinds of moths. The larvæ are aquatic, and construct a kind of case to reside in, from which circumstance they are often called case-worms. These cases are formed of various materials, and often present a singular appearance by being stuck over with small shells, pebbles, &c. The pupa is incomplete, and is enclosed in the case constructed by the larva, a grating being formed at the end, apparently for the purpose of facilitating respiration. The perfect insects are usually termed caddice-flies, and are frequently used, as well as the larvæ, by anglers as a bait for fish. They fly heavily, and commonly settle on bushes near the water's edge. Most of them are of a brown colour, with little variety of markings. Probably