Odontidium (hiemale). — (mesodon). — n. sp., same as at Piti on Conferva. Denticula (obtusa). Navicula. Cymbella, three species. Epithemia.
Scarcely any one of these except the Navicula is peculiar to the locality. A fragment apparently of some Closterium, the only one which I have met with in the collection, accompanies one of the specimens.
The hot springs of Momay, (temp. 110 degrees) at 16,000 feet, produce a golden brown Caenocoleus representing a small form of C. cirrhosus, and a very delicate Sphaerozyga, an Anabaina, and Tolypothrix; and at 17,000 feet, a delicate green Conferva with long even articulations. With the latter is an Odontidium allied to, or identical with O. turgidulum, and with the former a fine species of Epithemia resembling in form, but not in marking, E. Faba, E. (Zebra) a fine Navicula, perhaps the same with N. major and Fragilaria (virescens).* [Mr. Thomas Brightwell finds in a portion of the same specimen Epithemia alpestris, Surirella splendida, S. linearis, Smith, Pinnularia viridis, Smith, Navicula (lanceolata) and Himantidium (arcus).] In mud from one of the Momay springs (a), I detected Epithemia (Broomeii n.s.), and two small Naviculae, and in the spring (c) two species of Epithemia somewhat like E. Faba, but different from that mentioned above.
The hot springs of Soorujkoond, of the vegetation of which very numerous specimens have been preserved, are extremely poor in species. In the springs themselves and on their banks, at temperatures varying from 80 degrees to 158 degrees, at which point vegetation entirely ceases, a minute Leptothrix abounds everywhere, varying a little in the regularity of the threads in different specimens, but scarcely presenting two species. Between 84 degrees and 112 degrees there is an imperfect Zygnema with very long articulations, and where the green scum passes into brown, there is sometimes an 0scillatoria, of a very minute stellate Scytonema, probably in an imperfect state. Epithemia ocellata also contributes often to produce the tint. An Anabaina occurs at a temperature of 125 degrees, but the same species was found also in the stream from the springs where the water had become cold, as was also the case with the Zygnema.
The Diatomaceae consisted of:—
Epithemia Broomeii, n. s.
— thermalis, n. sp.
Epithemia inaequalis, n. sp.
Navicula Beharensis, n. sp.
The vegetation in the three sets of springs was very different. As regards the Confervae, taking the word in its older sense, the species in the three are quite different, and even in respect of genera there is little identity, but amongst the Diatomaceae there is no striking difference, except in those of the Behar springs where three out of the four did not occur elsewhere. In the Pugha and Momay springs, the species were either identical with, or nearly allied to those found in neighbouring localities, where the water did not exceed the ordinary temperature. A longer examination will doubtless detect more numerous forms, but those which appear on a first examination are sure to give a pretty correct general notion of the vegetation. The species are certainly less numerous than I had expected, or than might be supposed from the vegetation of those European hot springs which have been most investigated.
In conclusion, I shall beg to add a few words on the Fungi of the Himalayas, so far as they have at present been investigated. As regards these there is a marked difference, as might be anticipated from the nature of the climates between those parts of Tibet investigated by Dr. Thomson, and the more southern regions. The fungi found by Dr. Thomson were but few in number, and for the most part of very ordinary forms, differing but little from the produce of an European wood. Some, however, grow to a very large size, as for instance, Polyporus fomentarius on poplars near Iskardo, exceeding in dimensions anything which this species exhibits in Europe. A very fine AEcidium also infests the fir trees (Abies Smithiana), a figure of which has been given in the "Gardeners' Chronicle," 1852, p. 627, under the name of AEcidium Thomsoni. This is allied to the Hexenbesen of the German forests, but is a finer species and quite distinct. Polyporus oblectans, Geaster limbatus, Geaster mammosus, Erysiphe taurica, a Boletus infested with Sepedonium mycophilum, Scleroderma verrucosum, an AEcidium, and a Uromyces, both on Mulgedium Tataricum, about half-a-dozen Agarics, one at an altitude of 16,000 feet above the Nubra river, a Lycoperdon, and Morchella semilibera, which is eaten in Kashmir, and exported when dry to the plains of India, make up the list of fungi.
The region of Sikkim is perhaps the most productive in fleshy fungi of any in the world, both as regards numbers and species, and Eastern Nepal and Khasia yield also an abundant harvest. The forms are for the most part European, though the species are scarcely ever quite identical. The dimensions of many are truly gigantic, and many species afford abundant food to the natives. Mixed with European forms a few more decidedly tropical occur, and amongst those of East Nepal is a Lentinus which has the curious property of staining every thing which touches it of a deep rhubarb yellow, and is not exceeded in magnificence by any tropical species. The Polypori are often identical with those of Java, Ceylon, and the Philippine Isles, and the curious Trichocoma paradoxum which was first found by Junghuhn in Java, and very recently by Dr. Harvey in Ceylon, occurs abundantly on the decayed trunks of laurels, as it does in South Carolina. The curious genus Mitremyces also is scattered here and there, though not under the American form, but that which occurs in Java. Though Hymenomycetes are so abundant, the Discomycetes and Ascomycetes are comparatively rare, and very few species indeed of Sphoeria were gathered. One curious matter is, that amongst the very extensive collections which have been made there is scarcely a single new genus. The species moreover in Sikkim are quite different, except in the case of some more or less cosmopolite species from those of Eastern Nepal and Khasia: scarcely a single Lactarius or Cortinarius for instance occurs in Sikkim, though there are several in Khasia. The genus Boletus through the whole district assumes the most magnificent forms, which are generally very different from anything in Europe.
APPENDIX C.* [The tables referred to, at v. i. chapter ii, as under Appendix C., will be found under Appendix A.]