Five species occur in this country, the best known being _Panorpa communis_, which may be met with almost everywhere about hedge banks and in lanes. It is about half an inch long. The wings are transparent, with dark brown spots, which are more or less confluent. Another species, _Boreus hiemalis_, which possesses no wings, is found on the ground among leaves in the winter time. It does not exceed one-sixth of an inch in length, and is of a metallic-green colour. [Illustration: Fig. 50.--Bittacus Tipularius.] [Illustration: Fig. 51.--Boreus Hiemalis (Mag.)] SUB-ORDER 2.--TRICHOPTERA. The members of this group are the insects commonly known as Caddis Flies, and they are often ranked as a separate order by entomological writers. Nearly 600 species of _Trichoptera_ occur in Europe, of which about half the number are indigenous to the British Isles. The _larvæ_ are aquatic, and when full-grown prepare for themselves curious dwellings composed of sticks, stones, and other materials wherein to pass the pupa state. They may be seen almost everywhere where there is water. The caddis flies may be divided into two families, though the distinguishing marks are so minute that they really ought to be classified as one family only. To Mr. McLachlan we owe many thanks for his researches in this group of insects. [Illustration: Fig. 52.--Hydropsyche Montana.] [Illustration: Fig. 53.--Marronema Rubiginosa.] _Family 1, Inæguipalpia._--This family includes the largest species of the tribe, and are principally found in northern regions. One of our largest British species is _Phryganea grandis_, which measures four-fifths of an inch in length, and over two inches in expanse of the wing. It is an abundant insect, of a brown colour, with yellow rings on its _antennæ_, and the anterior wings are ash-coloured, clothed with brown. The _larvæ_ of this group for the most part inhabit quiet waters, ponds, canals, etc. This family is subdivided into three sub-families, viz., _Phryganeidæ_, _Limnophilidæ_, _Sericostomidæ_. _Family 2, Æguipalpia._--This family constitutes a second group, and also contains many species, many of them, however, being very minute insects, some hardly one-eighth of an inch across the wings. They make little cases of silk resembling seeds, to the outer surface of which they attach grains of sand, etc. The _Æguipalpia_ contains four sub-families--viz., _Leptoceridæ_, _Hydropsychidæ_, _Rhyacophilidæ_, and _Hydroptilidæ_. Of the _Leptoceridæ_, _Molanna augustata_ may be taken as a typical example, the larva of which lives on the sandy bottom of pools, and is very difficult to detect. SUB-ORDER 3.--PSEUDO-NEUROPTERA. In the third sub-order of the _Neuroptera_ are grouped together a series of insects which present great divergences of character, and really do not belong to the true _Neuroptera_ on account of their incomplete metamorphoses. They, however, for the most part, resemble the _Neuroptera_ in the structure of their wings.