XXXIX. Buxbaurnia. Capsule oblique, gibbous ; Xxxix. Buxbaurnia. Capsule oblique, gibbous ; peristome double ; the exterior-of numerous jointed fili form processes ; the interior a plaited membranous cone; calyptra mitriform.
This single moss was first discovered in Britain by Dr. Hooker. It has subsequently been found by Mr. E. Maughan, near Roslin ; by Mr. Jackson, near Aberdeen; and by the writer of this article, for three successive years, on the mountains of Nubie, Peeblesshire. This last habitat is much more abundant than any of the others, and does not appear likely to be exhausted.
This moss has now for some time been well known to have leaves, see Edin. Philos. Journal, vol. ii. p. 377 ; and the original description of Buxbaum, in which the capsule is said to be bivalve, is occasionally applicable to the plant in a state of decay.
XL. Bartramia. Fruitstalk terminal ; peristome dou ble ; the exterior of 16 teeth ; the interior a plaited mem brane, divided into 16 bifid segments ; calyptra dimidiate.
Contains six British species, none of which is peculi arly rare. Two new species, and two that had been previously dscribecl, are figured in the Alum Exot.
XLI. Bryum. Fruitstalks terminal; peristome dou ble ; exterior of 16 teeth ; interior a plaited membrane divided into 16 s.egments, usually alternating with cilia. Calyptra dimidiate.
Contains 25 British species, of which Br. triquetrum, and Br. rostratum, seem to be the most rare. Br. ros tratum, in most winter seasons, is abundant in fruit at Braid Hermitage. We have found the exterior teeth of Br. clealbatum, in specimens gathered at Gulane, to be exactly half the length of the cilia, making it a true Meesia. The fruit of Br. roseum is very rare. Three new species are figured in the Alusc, Exot.
XLII. Hookeria (of Smith.) Fruitstalks lateral; peXlii. Hookeria (of Smith.) Fruitstalks lateral; pe- ristome double ; exterior of 16 teeth ; interior of a mem brane divided into 16 entire segments, with sometimes cilia alternating. Calyptra mitriform.
Of this genus, two species arc British ; and Hook. Ixtevirens, found hitherto only in a bog near Cork, by :Mr. Drummond, is extremely rare. Its leaves are fur nished with two nerves running nearly to the summit. Six new species, and two that had been previously pub lished, are figu-red in the Alum Exot.
XLIII. Leskea.•Fruitstalks lateral, peristome double, Xliii. Leskea.•Fruitstalks lateral, peristome double, exterior of 16 teeth ; interior of a membrane divi-ded into 16 segments, with no cilia interposed. Cal) ptra dirnichate.
All the British Leskew are thrown into the genus Hypnum in the Aluscologia Britannica, on account of the difficulty in the discriminative character of these genera; and because, if the species in a topical flora be well ar ranged, they may be more conveniently discriminated without the separation. " But," says Dr Hooker, in No. 28 of the Alum Exot. in a work on foreign mosse, I think it right, at least for the present, to adopt the genus Leskea, though I must again repeat it as my opinion, that it is not founded in n.tture. Tne genus Hvpnum is now of such vast extent, that, in cases where the peristome can be well examined, i, is convenient to have recourse to such characters as are afforded by the Hedwigian families of Leskea and Hy plinth."
Under this generic name are described le the Illusc, Exot. seven new species.
XLIV. Hypnurn. Frnitstalks lateral ; peristomc douXliv. Hypnurn. Frnitstalks lateral ; peristomc dou- ble; exterior of 16 teeth ; interior a membrane divided into 16 segments, with alternate cilia. Calyptra diate.
Of llypna (including also under that name the genus Leskea,) the British flora contains 60 species. Of these, 11. reflexum, H. molle, H. moniliforme, a new species discovered in Ireland by Mr. Nlackay, II. catenulatum, H. rufescens, II. flagellare, H. blandovii, H. polymor phum, II. rugulosum, H. silesianum, and H. crista cas trensis, ti1C most rare. The fruit of various other species has been reckoned very rare, as, for instance, of H. dendroides, which has been found in great abundance by various botanists in the neighbourhood of Edinburgh. Sec Mr. Stewart's Hortus Cryptogamicus Edinenaqs, fasc. 1. The fruit of II. proliferum, II. alopecurum, H. Schreberi, H. squarrosum, the var. revolvens of H. aduncum, all of which are reckoned more or less rare in filth by Sir J. E. Smith, have also been found most abundant in that state in this neighbourhood, by various botanists. But the fruit of II. fluitans, cordifolium, II. stellaturn, and H. scorpioides, seems to be rare in the extreme in this neighbourhood, though formerly the late Mr. Don gathered H. cordifolium in fruit at Dud dine;ston Loch.
The number of new Hedwigian Hypna figured in the Muse. Exot. is 17 ; of which one species is doubtful. An additional species, H. flexile, had previously been repeatedly described.
*" Cilia numerous, arising- from the inner side of the walls of the capsule below the mouth, and from the coin 7/lella ! XLV. Dawsonia. Capsule convex on the one side, plane on the other; peristome penicillated, cilia very numerous, capillary, straight, equal, arising from the walls of the capsule, and from the columella. Exterior calyptra,a plexus of hails ; interior rough at the summit.
Of this very singular genus, only one species, D. poly trichoides, is known. It was discovered by Mr. Brown at Port Jackson, and the genus was named by him, in x. of Linn. Trans. after " that incomparable cryp togarnist," Dawson Turner, Esq. of Yarmouth.
The genus is introduced by Dr. ooker in the system, immediately aftcr Liellia. Natural affinity certainly brings it near to that genus and to Polytrichum ; but on account of its innumerable cilia, we prefer, with Bridel, placing it at the end of the system.
Such is the system of Dr. Hooker, a system which we think more likely to last than any other hitherto propos ed. The Doctor's pencil has so admirably illustrated every genus—we rnay add, every species of which he has treated—that no room is left to an attentive reader for mistake, or even doubt. And vve are persuaded, that it will not soon undergo any other material alteration, than the introduction of a new genera in the progress of discovery.
iMUSCI HEPATIC', DEOPERCU