-58 NEW ZEALAND NEUEOPTERA. 



thread-like, porrect, of many indistinct joints. Mandibles 

 absent or obsolete. Coxm elongate and free, but contiguous. 

 Metamorphosis great; larva caterpillar-like, usually in- 

 habiting cases of their own construction. Pupa resembling 

 the perfect insect in general form, becoming active previous 

 to the last ecdysis. Wingless forms of the imago excessively 

 rare " (Sharp). 



The following remarks will explain the principal terms employed by 

 systematists in classifying and describing these insects: — 



" The maxillary palpi vary much, but are always 5-jointed in the female. 

 The less are long and slender, and the tibiae are often furnished with spines 

 in addition to the movable spurs which are found at the apex and sometimes 

 near the middle of each tibia. These spurs usually differ in colour and in 

 appearance from the spines, and are important characters in classification. 

 The formula "2.4.4. means that the fore-tibia has a pair of apical spurs, while 

 the middle and hind-tibiae have median pairs in addition to the apical 

 pairs. 



" The neuration of the anterior wings is also very important in classifica- 

 tion, and the following remarks — taken from Mr. McLachlan — may help the 

 student. The anterior margin is called the ' costa. ' Parallel to the costa is 

 a nervine called the ' sub-costa. ' At the base of the wing the sub-costa emits 

 the ' radius,' which runs parallel to it. Near its base the radius emits the 

 ' sector,' which divides into two branches, each of which again divides. The 

 space between the two principal branches of the sector is closed by a trans- 

 verse nervule, and is called the ' discoidal cell.' Turning now again to the 

 base of the wing we find another longitudinal nervure below the radius. 

 This is the ' superior cubitus,' which almost immediately divides into two 

 branches, which again divide. At the first furcation of the upper branch 

 there is generally a semi-transparent whitish spot without any hairs, called the 

 'thyridium.' The 'inferior cubitus' is always fine and does not branch. 

 At the point of its termination on the inner margin of the wing there is 

 another transparent whitish spot, called the 'arculus.' The apical forks of 

 the sector and superior cubitus divide the extremity of the wing into a 

 number of apical cells, which are numbered from before backwards " 

 (Hutton). 



In their final condition the caddis-flies are not insects 

 ■of very special interest, being generally dull coloured, of 

 moth-like appearance, and rarely of large size. The 

 distinctions between the various species and genera 

 are, moreover, only to be appreciated by means of a very 

 minute examination of the flies, which can seldom be 

 successfully undertaken except by a specialist in the group. 

 Hence the family has been much neglected by general 

 •entomologists, and it is only through the labours of Mr. 

 McLachlan, and a few others, that a precise systematic 

 knowledge of these insects has been obtained. 



The Phryganeidse form the division or series Trichop- 

 tera; the two terms are therefore synonymous; those 

 entomologists, who consider these insects to form a distinct 

 -order, use the latter appellation for it. 



In striking contrast to the imagines, the earlier stages 



