the involucral leaves are fused with the perianth for part of their length. There are probably no true species of Nardia in New Zealand, and Stephani seems to have realised this when he removed Nardia humilis Berggr. and Nardia patellata Berggr. to the genus of Solenostoma, founded by Mitten for plants in which the perianth culminates in a tubular beak. This genus is now merged in Jungermannia, as the apical beak tends to disappear as the capsule ripens and breaks its way through.

The story of Nardia humilis Berggr., N.Z. Hep., 7, appears to be as follows: In the London Journal of Botany, 468, 1844, Dr. Taylor described a plant from Kerguelen Island (with stipules), which he called Jungermannia humilis. Later, in a Royal Society publication, 1879, Mitten stated that Taylor had described it wrongly, and that it had no stipules, for which reason he referred it to his new genus Solenostoma. On the strength of this and of the original drawing, Berggren decided that a New Zealand plant must be the same thing, but he gave it the name of Nardia humilis (Tayl.) Berggr. Stephani, however, in Species Hepaticarum, vol. 2, p. 50, definitely says that he had seen the Kerguelen Island plant, and that Taylor had described it correctly, and that it was not a Jungermannia (in the restricted sense), but a Lophocolea. He therefore, as mentioned before, referred Berggren's New Zealand plant to Solenostoma humilis (Berggr.) St.

In studying the various forms of this species, I have been quite unable to correlate the variations, with a view to delimiting a separate species. For instance, plants with large cells may be rose-coloured or dull green, very short with as few as two pairs of cauline leaves, or taller; perianth broad and sub-campanulate or cylindric-ovate, leaf-margins differentiated or doubtfully so, cell-walls not, or strongly thickened, trigones small or large. In one specimen the large basal cells extended well up the sides of the involucral leaves.

Plants with medium cells, ca. 30μ, and small trigones, also vary in size, with perianth short and sub-campanulate to as long as 2.5 mm., with a long neck; and here, again, the cell-walls of some or of most of the leaves may be very thick, and either fawn-coloured or beautifully rose-tinted.

From even smaller than the Handbook measurement of ¼–½ in. (Pearson's Solenostoma brevissima measures ¼ in.), the plant ranges to as much as 2.5 cm., often with delicate sterile stems with small distant leaves, intermingling with the main stems. The inflorescence is usually dioicous, but occasionally monoicous, as in a specimen from damp, open bank, E. of Taupo, 2,000 ft., K. W. Allison, 1935, and at least two gatherings from the Kiwi Hills, Wairoa, in all of which the ♂ bracts are in 3–4 pairs at the bases of stems with perianths. In tufts of plants from bank on side of Mangatangi Stream, Hunua Ranges, Auckland, L. B. Moore, the ♂ stems are separate, with the bracts basal. In plants from Stewart Island, Mrs J. D. Smith, stalked antheridia, 0.2 mm. in diameter, are in 1.2 pairs of bracts at the apex of the stem. Other ♂ plants have the bracts on the upper part of the stem, and on others the bracts constitute most of the cauline leaves.