The few examples of Arachnida found during the Transit of Venus Expedition to Kerguelen’s Land, were all apparently new to science. One, indeed, at present seems to me incapable of inclusion in any previously recognised order of Arachnids. The whole collection consisted of but five species; one of Araneidea, and three of Acaridea, the fifth, being that upon which I have founded a new genus, family, and order. At first sight this delicate little Arachnid gave me the idea of being a Chelifer deprived of its forcipated palpi; but a subsequent examination with a stronger lens showed me that it possessed palpi of an entirely different character from those of the pseudo-Scorpiones; and a final scrutiny under a still higher power led to the detection of the eyes: in the number and position of these there is displayed a remarkable similarity to the Solpugidea, while there are not wanting some general indications of affinity to the Araneidea. Its small size and general appearance when alive would probably induce one to refer it to the Acaridea; but the structure of the mouth-parts, the distinct cephalothorax and abdomen, and especially the character of the eyes, seem to preclude this allocation. It is possible, however, that when the Acaridea shall be more thoroughly worked out by some future arachnologist, the present anomalous little creature may become the type of a suborder, or perhaps of only a family of that order. Meanwhile in forming a distinct order for its reception, I desire to obtain the free criticism and opinion of arachnologists more conversant than myself with some obscure groups of Acaridea, as to its true systematic position. The following descriptions are reprinted from the Proc. Zool. Soc. Feb. 1876, pp. 259-265; and the plate is almost the same as in op. cit. pi. xix., the difference consisting chiefly in the addition of the figures of Tullbergia , and the greater enlargement of some of the others.