[Illustration: Fig. 400.--Semblis lutarius, imago, pupa, and larva.] M. Blanchard classes in the same tribe the genus _Semblis_, whose larvæ are aquatic, with scaly heads, provided with eyes, and with curved mandibles and short antennæ. The larvæ and the pupæ breathe, like those of the _Ephemeræ_, by articulated external processes, or gills, analogous to those of fishes. Nevertheless the pupæ live on land, not in water. They hide themselves in the earth at the foot of trees, and the adult issues forth at the end of a fortnight, leaving its pupa skin behind. It lives but a few days. The female lays her eggs on reeds, stones, &c. Fig. 400 represents the Mud _Semblis_ in its three states. [Illustration: Fig. 401.--Ant-lion (_Myrmeleo formicarius_).] We now come to those Neuroptera which undergo complete metamorphoses. They are the Myrmeleonidæ, of which the Ant-lion (_Myrmeleo_) is the most prominent type, and the _Phryganidæ_, or Caddis Flies. The larvæ of the Ant-lions live on the land, and are carnivorous. When about to undergo their transformation into pupæ, they spin for themselves a silky cocoon. The larvæ of the _Phryganeas_, on the contrary, live in the water. They surround themselves with a sort of protecting case, composed of a silky shell and incrustations of all sorts. The pupæ, as well as the larvæ of these insects, breathe by means of gills. [Illustration: Fig. 402.--Ant-lion's funnel.] [Illustration: Fig. 403.--Larva, cocoon, and pupa of the Ant-lion.] The Ant-lion (_Myrmeleo formicarius_, Fig. 401) is found in the environs of Paris. It is an elegant insect, resembling the dragon-fly, but is distinguished from it by its antennæ. Its larva is of a rosy, rather dirty grey, with little tufts of blackish hair on its very voluminous abdomen. Its legs are rather long and slender; the two anterior pair of legs are directed forwards, whilst the hind legs are fixed against the body, and only permit the animal to walk backwards. These larvæ are met with in great abundance in sandy places very much exposed to the heat of the sun. There they construct for themselves a sort of funnel in the sand (Fig. 402), by describing, backwards, the turns of a spiral whose diameter gradually diminishes. Their strong square head serves them as a spade with which to throw the sand far away: they then hide themselves at the bottom of the hole, their head alone being out, and wait with patience for some insect to come near. Scarcely has the ant-lion perceived its victim on the borders of its funnel, when it throws at it a shower of dust to alarm it, and make it fall to the bottom of the precipice, which does not fail to happen. Then it seizes it with its sharp mandibles, and sucks its blood; after which it throws its empty skin out of the hole and resumes the look-out. Ants especially become its prey, whence its name of Ant-lion. Towards the month of July, the larvæ make themselves a spherical cocoon, mixed with grains of sand, in which they are