146 MANDIBULATA. — TRICHOPTERA. 



Order V.— TRICHOPTERA, Kirhy. 



Wings all membranaceous, much deflexed, anterior pair more or less pilose, 

 posterior sometimes folded, all furnished with more or less branching 

 nervures, and very few transverse ones : mouth with merely rudimentary 

 mandibles : palpi four, dissimilar, maxillary occasionally long, labial short, 

 sometimes nearly wanting : maxilloE and labium membranaceous : body more 

 or less hairy : head small, transverse, vertical, flat above : eyes moderate, 

 semiglobose, prominent : ocelli two, frontal : collar small, transverse : 

 abdomen compressed-cylindric, not furnished with setse at the apex : legs 

 slender, coxoe elongate, tibia armed, in general, with two, three, or four long 

 spurs, sometimes spinulose : tarsi elongate, five-jointed, cylindric, furnished 

 with two small claws, and an intermediate cushion. Metamorphosis incom- 

 plete : larva aquatic, hexapod, active, elongate, subcylindrical, slightly 

 pilose ; head corneous, three following segments coriaceous, each having a 

 pair of legs; next frequently dilated and papillose, remainder variable, 

 being sometimes furnished with exserted branchial organs, and occasionally 

 with two caudal appendages : they mostly reside in a cylindric tube, lined 

 within with silk, and clothed without with various materials, according to 

 the groups to which they belong, as hereafter particularized : pupa quiescent, 

 being shut up in the case of the larvae ; it somewhat resembles the imago, 

 the limbs, &c. being distinct. The eggs are deposited in a gelatinous 

 mass. 



The insects included in this order are generally known by the name 

 of Case- or Caddice-flies, Water-moths, &c. In their larva state they 

 frequent running streams, lakes, ponds, &c. some species preferring 

 nearly stagnant waters, others the impetuous torrents of mountain- 

 streams, &c. : they are consequently always to be found in marshy 

 districts, and usually make their appearance during the summer 

 months, though some few species do not occur till the autumn : in 

 general habit they greatly resemble each other, and from the almost 

 total uniformity of colouring that obtains amongst them, they are 

 extremely difficult to divide specifically from each other : never- 

 theless, by a careful attention, sufficiently powerful characters of 

 distinction may be detected, not only in the colouring, but also in 

 the neuration of the wings. Continental naturalists almost universally 

 agree in placing these insects as a great section of the Neuroptera, 

 in which respect they have been partially followed in Britain, but I 

 conceive their characters, especially those drawn from their wings, 

 which are pilose, and have branching nervures, like the Lepidoptera, 

 are unlike any of the true Neuroptera : their coxae and legs are also 



