[Illustration: Fig. 129.--Ceratopogon Femoratus (Mag.)] One of the most troublesome species is probably the House Gnat (_Culex ciliaris_), which, thirsting for its evening meal, often enters our apartments, sounding its approach by a tolerably loud humming. [Illustration: Fig. 130.--Trichocera Fuscata (Mag.)] _Culex annulatus_ is a little larger, and is said to produce a greater amount of irritation by its bite. _Family 7, Chironomidæ._--These insects are small delicate insects, much resembling gnats in appearance, and are popularly called "Midges." The _larvæ_ of most of the species are aquatic. The _larva_ of _Chironomus plumosus_, which is common in stagnant water, is called the "blood worm" from its bright red colour. [Illustration: Fig. 131.--Tipula Gigantea.] _Family 8, Orphnephilidæ._--Most of the species belonging to this family are of small size. The typical species is _Orphnephelia testacea_, measuring scarcely one-tenth of an inch in length, and is sometimes found in bakehouses. It is of a rusty-yellow colour. _Family 9, Psychodidæ._--This is a small family consisting of minute brown or yellowish species remarkable for their resemblance to moths. They mostly feed on fungi and decayed vegetable substances. The species of _Phlebotomus_ are troublesome blood-suckers in the south of Europe. _Family 10, Tipulidæ._--The insects belonging to this group are popularly known as Crane Flies and Daddy-longlegs. They are very abundant. The commonest species, _Tipula oleracea_, is a grey species with transparent wings, and exceedingly destructive to corn, roots of grass, etc., and no effectual remedy has hitherto been discovered for preventing their attacks. The familiar Winter Gnat (_Trichocera hiemalis_) belongs to this family. It may often be seen, even during the dreary months of December and January, dancing to and fro under the shelter of some hedge or wall. In frosty weather it conceals itself beneath the bark of trees, under leaves, etc. [Illustration: Fig. 132.--Erioptera Grisea (Mag.)] _Family 11, Dixidæ._--This family of gnats frequents damp places in woods, and are therefore designated "Wood Gnats." They may occasionally be seen during the summer time in immense swarms. The species of _Dixa_ are reddish, yellow, or black insects generally of small size. _Family 12, Rhyphidæ._--The _larvæ_ of most of these insects feed upon decayed vegetable matter. The species of _Rhyphus_ may often be found resting on leaves in damp situations, they may also be seen on windows, and occasionally "dancing in the air." They are generally brown, yellow, or grey insects of small size. TRIBE II.--BRACHYCERA. These insects are generally of much larger size, and more robust in appearance than those contained in the previous tribe. They are divided into twenty-two families. [Illustration: Fig. 133.--Stratiomys Chameleon.]