Whether these nests are equally showy we cannot tell, as the account is brief and few details are given; but one, that of Cyrtocephalus terricola, appears to differ in having threads stretched from the opening of its funnel, which serve to ensnare insects and to give notice of these captures.
The great trap-door group therefore comprises spiders which differ widely in respect of their dwelling places. Some construct no nest at all or only an irregular web, and live under stones; others, like Theraphosa Blondii, make a simple cylindrical tunnel, or, like those just described, a tube having a prolonged, uncovered, funnel-shaped mouth: others again, belonging to the genus Atypus, form the curious and as yet imperfectly-understood nests with a silken tubular lining, part of which hangs down outside; while on the highest rung of the architectural ladder, stand the builders of the veritable trap-door nests.
It seems quite possible that, when we know more of the structures made by Territelariæ generally in various parts of the world, we shall find that nests of various degrees of complexity and perfection of structure exist, bridging over the gulf between the barbarous dwellers under stones and the highly civilized inhabitants of the branched wafer and cork nests.
Indeed, thanks to recent discoveries, I am already able to do something of this kind for one small group of spiders, namely, for that of the European Nemesias having nests with wafer doors.
I hope to make this plain by reference to the diagrams on Plate XIV., where the figures C, D, E, F,
