CADDIS-FLIES. 61 



model of the external structure of the pupa, and contains 

 a considerable number of tracheae. 



The eggs of caddis-flies are deposited in a singular 

 manner ; they are extruded in a mass surrounded by 

 jelly ; there may be as many as one hundred eggs in 

 such a mass. This is sometimes carried about by the 

 female after its extrusion from the interior of the body, 

 but is finally confided to a suitable place in the stream 

 or pool. 



The Phryganeidae are frequently regarded as the 

 nearest existing allies to the great order Lepidoptera ; 

 moths and butterflies are thus supposed to have originally 

 descended from some ancient form of insect, closely 

 resembling our existing caddis-flies. Although not at 

 present borne out by the discovery of fossil remains, 

 there are no doubt many facts in connection with the 

 structure and habits of these insects which strongly 

 support the above idea, and the subject has been 

 •discussed at some length in several modern works on the 

 Lepidoptera. 



The Phryganeidae are at present represented in New 

 -Zealand by the following five sub-families only : — 



1. Sericostomatides. 3. Hydropsychides. 



2. Leptocerides. 4. Rhyacophilides. 



5. Hydroptilides. 



Sub-Family 1.— SERICOSTOMATIDES. 



" Maxillary palpi of the male 2- or 3-jointed, ordinarily very pubescent 

 or pilose, and always formed in quite a different manner from those of the 

 female ; varying greatly according to the genus. Larva with non-fasciculate 

 respiratory filaments ; the case free" (Hutton). 



In this group the larvae mostly inhabit streams. 

 They construct movable cases out of sand and stones 

 in preference to vegetable matter. The respiratory 

 filaments are filiform. 



Genus GECONESUS, McLachlan (1862). 



" Male. — Head quadrate ; antennae about the length of the wings, basal 

 joint short and rather thick, not so long as the head. Maxillary palpi oval- 

 elongate, much swollen, curved up in front of the head, their apices when 

 viewed from above appearing as two rounded tubercles between the antennse, 

 moderately hairy. Labial palpi with the basal joints short, the second and 

 third of equal length, long. Anterior tibiae with two short spurs ; inter- 

 mediate and posterior, each with four long unequal spurs. Anterior wings 

 rather short and broad, very slightly hairy, the costa much arched, apical 



