_Apoica pallida_, a South American Insect, forms a nest in a somewhat similar manner to _Polistes_, but it is covered on its outer aspect by a beautiful paper skin, so that the nest looks somewhat like a toadstool of large size attached to the branch of a tree. The nests of the Insects of the genus _Polybia_—which we have already mentioned as located by de Saussure in his unsatisfactory group Poecilocyttares—usually have somewhat the form and size of pears or apples suspended to twigs of trees or bushes; these little habitations consist of masses of cells, wrapped in wasp-paper, in which there are one or more orifices for ingress and egress. Smith says that the combs in the nest of _P. pygmaea_ are of the most exquisite construction, and that it is by no means an uncommon circumstance to find the outer envelope of the nest ornamented with patches of delicate hexagonal tracery. This nest is about the size of an orange. We have already noticed the variety of nests formed by our British species of the genus _Vespa_; in other parts of the world the edifices formed by species of _Vespa_ attain a very large size. _V. crabroniformis_ in China, and _V. velutina_ in India, make nests several feet or even yards in length, inhabited by an enormous number of individuals; they are apparently constructed of a material like brittle paper, and are arranged much like the nests of our British hornet, _V. crabro_. _Vespa orientalis_ mixes a considerable quantity of earth with the paper it uses for its {84}constructive efforts. In the British Museum collection there is a nest said to be that of the Japanese hornet, _V. japonica_. This is completely covered by a paper envelope, and has apparently only a single small orifice for ingress and egress. In the same collection there is a nest from Bahia (believed to be that of a social wasp, though of what species is unknown), the outer wall of which is apparently formed entirely of earth, and is a quarter or half an inch thick: the comb inside appears also to be formed of clay, the whole forming an elaborate construction in pottery. One is tempted to believe it may prove to be the production of a social Eumenid.