the body becomes much swollen and the legs are much shortened, as are also the antennae, the head becoming small and the general appearance reminding one of the larva of a bee. [Illustration: FIG. 36.--Lace-wing fly. _a_, eggs, _b_, larva, _c_, cocoons, _d_, fly with left wings removed.] [Illustration: FIG. 37.--An Ant-lion (_Myrmeleon_). (From Packard.)] [Illustration: FIG. 38.--Myrmeleon larva.] [Illustration: FIG. 39.--_Mantispa_ with side view beneath. (From Packard.)] The second section of the Neuroptera, characterized by complete metamorphosis, comprises the following suborders: Suborder PLATYPTERA ([Greek: platys], flat; [Greek: pteron], wing). Under this head are grouped the White-ants (_Termitidae_), the Bird-lice (_Mallophaga_), and the Book-mites (_Psocidae_). The suborder receives its name from the fact that in the case of the winged forms the wings, when at rest, are usually laid flat upon the back of the insect. The Mallophaga, or Bird-lice, are degraded wingless insects, and are parasitic chiefly on birds, but also on mammals. In shape of body and character of the mouth-parts they are most nearly allied to the Psocidae. The latter family includes both winged and wingless forms, the Book-mites belonging to the latter category. The winged forms may be illustrated by the common species, _Psocus venosus_ (see Fig. 40). The legs and antennae are long and slender and the wings are folded roof-like over the body when the insect is at rest. They feed on lichens and dry vegetation. The Termitidae are represented in this country by the White-ant (_Termes flavipes_), which is frequently so destructive to woodwork, books, etc. The term White-ant applied to these insects is unfortunate, as in structure they are widely separated from ants and resemble them only in general appearance and also in their social habits. Like the ants they live in colonies and have a number of distinct forms, as winged and wingless, males and females, and workers and soldiers. [Illustration: FIG. 40.--_Psocus venosus._ (From Comstock.)] Suborder PLECOPTERA ([Greek: plektos], plaited; [Greek: pteron], wing). Closely allied to the latter suborder is the suborder Plecoptera, which includes the single family Perlidae or Stone-flies. The larvae and pupae of these insects are aquatic, being often found under stones in water, whence the name. The adults are long, flattened insects, with long antennae. The wings are ample and are somewhat folded or plaited, from which character the suborder takes its name. [Illustration: FIG. 41.--A Stone-fly (_Pteronarcys regalis_). (From Comstock.)] Suborder ODONATA ([Greek: othous], tooth). This includes the Dragon-flies or Libellulidae, the most common and the best known of the Neuroptera. The larva and the active pupa or nymph are aquatic and are predaceous, as is also the adult. A common species is represented at Fig. 33.