haps in this genus, as among the Polistes, workers are wanting (see Fig. 2).
The wasps hitherto considered are distinguished as manufacturers of paper, in general fine and thin and more or less brittle, the weakness of which they overcome by the superposition of a great number of leaves. There is a large class who, while they make many kinds of papyraceous tissues, are noted for a feature in common—the fabrication of a solid and tough paper, a veritable cardboard, composed of only one layer of material, at times very thick and resisting, at others slight and supple. Of this substance, after the manner of Vespa, the wasps usually build a papyraceous envelope or sac for the inclosure of their combs, and as in that genus, the covering follows closely the direction of the plan of the cells.
The genus Chartergus, one of the important groups of the cardboard makers, includes insects apparently similar which practice two strangely different forms of nidification. The nests of C. chartarius, the most common in collections, are of frequent occurrence in tropical America. Their cardboard is white, gray, or of a buff color, tending to yellow, very fine and of polished smoothness; at the same time it is strong and so solid as to be impervious to the weather. It can not be urged sufficiently, says Réaumur, that this kind of envelope is indeed of a veritable cardboard, as beautiful as any we know how to make. Réaumur once showed a piece to a cardboard manufacturer, and not the slightest suspicion of its real nature was suggested to his mind. He turned it over and over, he examined it thoroughly by the touch, he tore it, and after all declared it to be made by one of his own profession, mentioning manufacturers at Orleans as the probable producers. The nests may be conical or cylindrical, they may be straight, but more often are somewhat curved; some are almost globe-shaped, but these varieties are of little importance. The length of a well-sized nest is about a foot; the largest yet discovered was in Ceylon, and measured the astonishing size of six feet. The edifice is pendulous on trees and attached, as it were, to a suspensory ring, which embraces the branch and is tightly impasted round it, or, according to Westwood, may be large compared with the latter's circumference; but it is probably a mistake to say that the nest ever swings freely as on a pivot. The interior consists of circular concave horizontal platforms of cells, their mouths turned downward, each tier stretching right across like so many floors, and fastened along its entire edge to the walls. Communication is effected by a central opening through the bottom and through every tier. When the number of inhabitants becomes very great and a fresh series of cells is added, unlike the British wasps who add to their abodes by a preliminary in-
