During the examination of the materials from which the genus Hymenophyllum was described in the second part of the " Species Filicum," I had but cursorily investigated the Auckland Island species, and considered the H. minimum of Richard to be a small variety of II. Tunbridgenae, with terminal involucres. This state is not uncommon in the vicinity of the Bay of Islands, and this I laid before my father ; whence the H. minimum was by him included as a synonym of that widely diffused species. Amongst my specimens of H. multifidum I now find others of this very minute and most distinct plant, which have enabled me to correct that error. In the rigid consistence of the frond, its decurved habit and lurid colour, it is more nearly allied to H. multifidum than to any other species, but the curiously spimdose valves of the involucre afford an excellent specific character, as do the small size, simple frond and singularly concave segments, which appear like the half of a tube, that is, hollow throughout their length and open at the end. Between this plant and the Trichomanes ccezpitosum of the Falkland Islands and Cape Horn, much analogy exists, especially in size, locality and habit ; in each the fronds are generally once divided, with the segments concave and obtuse ; both have the indusia free or nearly so, spimdose at the back of the valves, and though often lateral in the latter plant, the fructifications are, especially on small specimens, very generally terminal, and may prove to be truly lateral in II. minimum, shoidd that plant be found in a more luxuriant state than M. Richard's or my specimens exhibit. In the ' Flora Novas Zelandiae ' M. Richard does not mention the original discoverer of the species ; the figure in the ' Voy. de la Coquille ' is not characteristic of the curious involucres.
2. Hymenophyllum multifidum, Sw. Syn. Fil. p. 149 and 378. Hook, and Grev. Ic. Fil. t. 165. Presl, Hj/menop/iyll. p. 32. Hook. Sp. Fil. vol. i. p. 98.
Hab. Lord Auckland's group and Campbell's Island ; in all situations, from the level of the sea to the tops of the mountains, growing on the ground, on trunks of trees and on rocks.
A very common New Zealand fern, from the latitude of the Bay of Islands to that of Campbell's Island ; representing in this region the H. tortuosum of Antarctic America and the H. Tunbridgense of the Northern Hemisphere. It is very variable in size, but the fronds are always remarkably bent downwards, their apices often touching the ground.
3. Hymenophyllum demissum, Sw. Sgn. Fil. p. 147 and 374. ScMuhr Fil. 1. 135. c. F. Rich. Fl. Nov. Zel. p. 92. Hook. Sp. Fil. vol. i. p. 109. Sphaerocioniuni deinissvun, Presl, Ilymenophi/ll. p. 35. Hab. Lord Auckland's group ; in dense woods near the sea, often covering the ground with large patches of a lurid green colour.
The specimens of this beautiful species are smaller than those collected in the northern island of New Zealand, but do not otherwise differ,
Mr. Presl's genus Sphrerocionium is apparently founded only upon the form of the receptacle, in its being "shorter than the indusium, naked and cylindrical below, and thickened and globose at the apex, which alone bears the capsides ; " such characters can hardly be applied to this species, where the receptacle, though short, produces capsules for at least two-thirds of its length, the lowest portion or thud part only being naked and cylindrical, gra- dually thickening upwards into an elongated club-shaped body.
The structure of the receptacle in most species of the genus Hymenophyllum, in its more extended sense, appears to me very uniform ; in length it varies extremely, but there is generally a short cylindrical body, which may be considered a pedicellus to the elongated capsuliferous portion or true receptaeulum ; upon the comparative length of this latter portion the genus of Presl rests. In some New Zealand specimens of this fern the pedicel is so short as to be almost obliterated, the receptacle appearing like a stout column covered throughout its length with capsules ; in others the whole organ is reduced to an elevated tubercle in the bottom of the involucre. Of the other plants included by Mr. Presl under this genus I have examined several ; of these, S. infortunatwn, the only
