The last production which made its appearance on our wall-paper burst through the varnish as little black spheres, like grains of gunpowder. At first the varnish was elevated by pressure from beneath, then the film was broken, and the little blackish spheres appeared. These were, in the majority of cases, gregarious, but occasionally a few of the spheres appeared singly, or only two or three together. As the whole surface of the damp paper was covered by these different fungi, it was scarcely possible to regard any of them as isolated, or to declare that one was not connected with the mycelium of the others. The little spheres, when the paper was torn from the wall, were also growing from the under surface, flattened considerably by the pressure. The spherical bodies, or perithecia, were seated on a plentiful hyaline mycelium. The walls of the perithecia, rather more carbonaceous than membranaceous, are reticulated, reminding one of the conceptacles of _Erysiphe_, to which the perithecia bear considerable resemblance. The ostiolum is so obscure that we doubt its existence, and hence the closer affinity of the plant to the _Perisporiacei_ than to the _Sphæriacei_. The interior of the perithecium is occupied by a gelatinous nucleus, consisting of elongated cylindrical asci, each enclosing eight globose hyaline sporidia, with slender branched paraphyses. A new genus has been proposed for this and another similar form, and the present species bears the name of _Orbicula cyclospora_.[V] The most singular circumstance connected with this narrative is the presence together of four distinctly different species of fungi, all of them previously unknown and undescribed, and no trace amongst them of the presence of any one of the very common species, which would be supposed to develop themselves under such circumstances. It is not at all unusual for _Sporocybe alternata_, B., to appear in broad black patches on damp papered walls, but in this instance not a trace was to be found. What were the peculiar conditions present in this instance which led to the manifestation of four new forms, and none of the old ones? We confess that we are unable to account satisfactorily for the mystery, but, at the same time, feel equally unwilling to invent hypotheses in order to conceal our own ignorance. [A] These predilections must be accepted as general, to which there will be exceptions. [B] Viviani, "I Funghi d'Italia." [C] Badham's "Esculent Funguses," Ed. i. pp. 42, 116. [D] An excellent white Agaric occurs on ant nests in the Neilgherries, and a curious species is found in a similar position in Ceylon. [E] Westendorp, "Les Cryptogams après leurs stations naturelles." [F] Cooke, "On Nettle Stems and their Micro-Fungi," in "Journ. Quekett Micro. Club," iii. p. 69. [G] Westendorp, "Les Cryptogams après leurs stations naturelles," 1865. [H] "Gardener's Chronicle," 1874.