Family 3, Mantispidæ.—This family contains only one genus—viz., Mantispa, or the Mantis Flies. A single species, Mantispa pagana, is common in southern Europe, but does not occur in the British Isles.
Family 4, Sialidæ.—In the fourth family of the Planipennia the larvæ are aquatic in their habits with very few exceptions. The pupa is not enclosed in a cocoon as it is in the Hemerobiidæ. The single common British species (Sialis lutaria) is a blackish-brown insect, rather more than half an inch in length. It is well known to anglers, and may be found abundantly in the spring and early part of the summer upon walls and palings in the neighbourhood of water, and upon the stems and leaves of grasses and other plants growing in the water or upon its bank.
In repose the wings of this insect, as in the Hemerolicidæ, are laid over the back. They are sluggish creatures, and do not readily take to flight.
Family 5, Raphiidæ.—This family contains the curious group of insects called "Snake Flies" or "Camel Flies," which are included by some entomologists in the previous family. They have characteristics, however, which entitle them to be placed apart. They have a rather large head, which is attached to a greatly elongated prothorax by a thinnish neck, so that the head has considerable freedom of motion. The species are not numerous, four kinds only occurring in Britain. The larvæ reside under the bark of trees, where they feed upon minute insects. The commonest species is probably Raphidia megacephala.
Fig. 48.—Raphidia Ophiopsis (Mag.)
Fig. 49.—Panorpa Communis.
Family 6, Panorpidæ.—The Panorpidæ, or Scorpion Flies, are very curious creatures, characterised above all things by the perpendicularly placed and greatly elongated head.