444 INSECTA. 



They comprise the genus 



Perla, Geoff. 



Their body is elongated, narrow and flattened; the head is tolerably large, 

 the antenna are setaceous, and the maxillary palpi very salient. The first 

 segment of their trunk is nearly square, and the wings are crossed and laid 

 horizontally on the body; the abdomen terminates as usual by two articu- 

 lated setje. 



Their larvae are aquatic and inhabit sheaths or cases, which they construct 

 in the manner of those formed by the Insects of the ensuing family, and in 

 which they pass into the state of nymphs. 



FAMILY III. 



PLICIPENNES(l). 



In this family the mandibles are wanting, and the inferior wings 

 are usually wider than the others, and plaited longitudinally. It is 

 formed of the genus 



Phryganea, Lin. Fab. 

 These Neuroptera at a first glance, have the appearance of little Phals- 

 nae, and hence the name of Mouches papillonacees or papilionaceous flies, 

 bestowed upon them by Reaumur. The body is most frequently bristled 

 with hairs, and, with the wings, forms an elongated triangle, hke several of 

 the Noctuse and Pyrales. The first segment of the thorax is small. The 

 wings are simply veined, usually coloured, or almost opaque, sUky or pilose 

 in several, and always strongly teetiform. The legs are elongated, are 

 furnished with small spines and have five joints in all the tarsi. 



These Insects chiefly fly at night or during the evening, diffuse a disa- 

 greeable odour, frequently penetrate into houses, where they are attracted 

 by the light, and are extremely quick and agile in all their motions. The 

 smaller species flit about in flocks over ponds and rivers. 



Their larvje, always, like the Tinese, inhabit tubes that are usually cylin- 

 drical, covered with various substances which they find in the water, such 

 as blades of grass, bits of reeds, leaves, roots, seeds, grains of sand, and 

 even little shells, and frequently arranged symmetrically. They connect 

 these various bodies with silken threads, the source of wliich is contained 

 in internal reservoirs similar to tliose of Caterpillars, and that are also pro- 

 duced by fusi situated in the lip. The interior of the habitation forms a 

 tube which is open at both ends for the intromission of water. The larva 



(1) Folded-wings. 



