Fig. 1. Tuft of Dicranum phascoides (nat. size). Fig. 2. Sterile plant. Fig. 3. Female plant. Fig. 4. Male plant. Fig. 5. Cauline leaf. Fig. 6. Perichætial leaf. Fig. 7. Leaf surrounding and including a male flower. Fig. 8. Capsule. Fig. 9. The same, having cast its operculum, and showing the peristome and part of the annulus. Fig. 10. Portion of the annulus. Fig. 11. Teeth of the peristome:-magnified.

RICCIA NATANS.

CRYPTOGAMIA HEPATICÆ. Nat. Ord. HEPatică.

GEN. CHAR. Capsula substantia frondis immersa, membranacea, indehiscens, demum evanescens, stylo protruso terminata, seminibus tuberculatis repleta.

Riccia natans; fronde obovata cordatave dichotome lobata, lobis rotundatis margine subtusque longe fimbriatis, fimbriis reticulatis serrato-dentatis. (TAB. XXII.)

Riccia natans. Linn. Syst. Nat. ed. 12. v. 2. p. 708. Smith, Engl. Bot. t. 252. Spreng. Syst. Veget. v. 4. p. 236.

Riccia capillata. Schmidel Icones. p. 276. t. 74.

Lemna dimidiata. Rafinesque in Amer. Monthly Magaz. v. 1. (fide Torrey.)

HAB. In aquis stagnantibus per totam fere Europæam.-In America Septentrionali capsulas proferens prope Novam Eboracensem. Dr. Torrey.

Frondes subcongestæ aquæ superficiei natantes, semiunciam longæ, simplices, nunc obovatæ, emarginatæ, nunc obcordatæ, bis terve dichotome lobatæ, lobis rotundatis, planæ, carnoso-membranaceæ, intus cellulosa, læte virides, reticulatæ, obscure costatæ, margine sæpe purpurascentes, subtus margineque dense fimbriatæ, fimbriis lineari-acuminatis, sub lente reticulatis, membranaceis, dentatoserratis, viridibus vel sæpissime purpurascentibus. Capsula

semper

in costam sitæ, substantia immersæ, superne convexæ, intus granulis vel seminibus numerosis, minutis, subsphæricis, tuberculatis, nigris repleta.

THE fructification of this (hitherto) supposed species of Riccia has long been a desideratum; and though the plant has been known for a considerable time to the botanists in Europe, yet no specimens in fruit had been seen by them. At length in 1824 Dr. Torrey, Professor of Natural History at the Military Academy at West Point, New York,

was so obliging as to send me specimens in that state from the neighbourhood of that place, which I have already mentioned in the second edition of the Muscologia Britannica. These I think prove beyond a doubt that the plant is rightly placed in the genus Riccia; at the same time I must acknowledge that the fructification, in the only specimen I have yet received, is too far advanced to allow me to distinguish the capsule itself. But I know that in our common R. crystallina this part is thin and evanescent, and masses of seeds, from two or three or more capsules at length become confluent in the substance of the frond, and escape by the decay of the epidermis above them, leaving cavities or hollows in the frond. It is the case here also, and the seeds are of precisely the same nature in both.

Fig. 1. Plant of Riccia natans (nat. size), Fig. 2. Fructified plant. Fig. 3. Portion of the same, to show the inside of a capsule. Fig. 4. Another portion, showing the seeds of several capsules conglomerated. Fig. 5. Seeds. Fig. 6. Portion of the epidermis of the plant:-magnified.

PARNASSIA FIMBRIATA.

PENTANDRIA TETRAGYNIA. Nat. Ord. DROSERACEÆ.

GEN. CHAR. Cal. pentaphyllus. Petala 5. Squamæ 5, unguibus petalorum oppositæ, in setas apice glandulosas (plerumque) desinentes. Stamina 5. Antheræ posticæ. Stigmata 4, sessilia. Capsula 4valvis, 1-locularis, valvis medio septiferis. Semina arillata. (DeC.) Parnassia fimbriata; squamis subpalmatis eglandulosis, petalis basi ciliatis, foliis radicalibus longe petiolatis reniformibus, caulina cordata sessili. (TAB. XXIII.)

Parnassia fimbriata. Kön. in Ann. of Bot. v. 1. p. 391. Smith in Rees, Cycl. Decand. Prodr. v. 1. p. 320.

HAB. In ora occidentali America Septentrionalis. D. Menzies. In montibus "Rocky Mountains" dictis. D. Drummond.

Radix horizontalis, subfusiformis, fibrosa, superne basibus petiolorum vetustorum vestita. Caulis pedalis ad sequipedalem, erectus, gracilis, subangulatus, prope vel supra medium, unifoliatus. Folia radicalia 3-6, longe petiolata, reniformia, integerrima, multinervosa, caulinum parvum, cordatum, sessile. Flos terminalis, solitarius. Calyx 5-partitus, vel fere pentaphyllus. Petala 5, alba, obovata, subunguiculata, patentia, nervosa, ad basin pulcherrime ciliata. Squamæ 5, viridi-flavescentes, fusco-punctatæ, petalis oppositæ, carnosa, cuneata, apice quinquelobæ, intus linea elevata longitudinali instructæ. Stamina 5, demum patentia: Antheræ oblongo-ovales, pallide flavæ, punctatæ. Pistillum: Germen ovatum: Stigmata 4, sessilia.

No botanist that I am aware has ever seen this very curious species of Parnassia in a living state, except Mr. Menzies, who had the gratification of discovering it on the north-west coast of America, and Mr. Drummond, who more recently found it in the interior, growing in pastures and marshy grounds, on the sides of mountains, particularly near the banks of lakes and rivulets. From a drawing and descrip

tion made on the spot, aided by specimens communicated by Mr. Menzies, the present figures and descriptions are published.

Mr. Menzies observed that the stamens, after having performed their office of fertilizing the stigmas, which they do by approaching the pistil in succession, each remaining some time in contact with the stigmas, fall back in a horizontal position between the petals, giving an appearance of great regularity to the whole flower. It will be seen that in the structure of the scales or nectaries of the flower, the present species departs from the character hitherto laid down for the genus; but not sufficiently so to constitute a new one: and in habit the plant entirely accords with Parnassia.

Fig. 1. Petal. Fig. 2. Stamen. Fig. 3. Scale or Nectary :-magnified.