CLASS XXI. ORDER IV. 69 



turity, towards the midrib, or remains closed. The fertile leaves are contracted 

 and narrower than the barren ones, (sensitive polypod.) 



B. Capsule without a ring—being cellular-reticulate, pellucid, sui-striate, radiate 

 at the tip. 



Osmun"da. Capsules globose, pedicelled, radiate-striate or wrinkled, having 

 a hinge at the joining of the 2 valves, which resembles part of the jointed ring 

 of annulated ferns; the capsules either occupy the whole frond, to a limited 

 extent, or a panicled raceme. The parts of the frond occupied by the fruit, 

 are always more contracted than the barren parts, (flowering fern.) 



C. Snb-order, Apteres — loithotU pirmate, pinnatijid, or other whiged leaves. 



Lycopo'dium. Capsules mostly kidney-form, or roundish, 2 or4-valved, open- 

 ing elastically; they are placed under separate scales in a spike, or sometimes 

 in the axils of the leaves. Leafy, their stems being generally covered with 2, 

 3, or 4 rows of narrow, simple, entire leaves, (ground pine.) 



Equise'tum. Fruit placed under peltate polygons, being pileus-like bodies, 

 which are arranged in whorls, forming a spike-form raceme; 4 to 7 .spiral fila- 

 ments surround the seed, which resemble green globules. Fertile plants mostly 

 leafless ; the stems of all are jointed with toothed sheaths at every joint, and 

 usually longitudinally striated and hollow, (scouring-rush, horse-tail.) 



ORDER II. MUSCI. 



Fhna'ria. Teeth of the outer peristome* 16, cohering together at the apex, 

 and twisted obliquely; the inner peristome consists of 16 membranaceous hairs, 

 opposite to the teeth, lying flatly. 



PoLYTRi"cHUM. Peristome Very short; teeth 16, 32, or 64; mouth of the germ 

 covered by a dry membrane, which is connected to it by the teeth of the peris- 

 tome ; calyptra very small, with a large villose or hairy covering. 



ORDER III. HEPATICE. 



Marchan"tia. Receptacles pedicelled, radiate-lobed, disk-like, or bell-form, 

 with the inside downward, to which the globose 4-valved capsules are attached 

 with their apexes downward. The umbrella-like receptacle is elevated one or 

 Iwo inches by a stipe attached to the centre of its lower side, among the cap- 

 sules, and many pilose appendages. The frond is leafy, reticulate, furnished 

 with a midrib, and beset with villose roots on the under side, which attach them- 

 selves to the stones in brooks, to damp earth, &c. 



.Tungekman"nia. Capsules 4-valved, globose, elevated by peduncles or stipes 

 from within a bell-form calyx. The fronds are made up of finer leaves than 

 those of the Marchantia, and are often mistaken for mosses, among which they 

 generally grow. 



ORDER IV. ALG^. 



A. The section FucoiDEffi comprises those sea-tceeds of the old genus Fucus, whose 

 fronds are cartilaginous or leathery, and of an olive or copper colour, becoming 

 brown or black. They are composed of intcriooven, longitudinal fibres. The 

 floating vesicles apper like portions of the frond blown up in bubbles. 



Fu'cus. Receptacles tubercled ; tubercles perforated, nourishing aggregated 

 capsules within, intermixed with articulated fibres. 



B. The section Florwv^e comprises those sea-weeds of the old genus Fuc^ts, whose 

 fronds are leathery, membranous or gelatinous, and of a p^irple or rose colour. 

 HALyME'NiA. Frond membranaceous, leathery, nerveless, punctate; seed im- 

 mersed thjoughout the whole frond, disposed in spots. 



C The section Ulvoideje comprises the iplajits of the old genus Viva. Fronds 

 membranaceous, {broad, or in narrow slips,) thin, of a grass-green colour. Their 

 substance consists of cells, with the fruit immersed in the frond. Tfcey grow on 

 rocks, stones, shells, d^c. in the sea; also in ditches, stagnant waters, damp 

 woods, ^c. 

 Ul"va. Seeds in fours, immersed in every part of the membranaceous frond, 



D. The section Confervoide^ comprises the plants of tlie old genus Conferva. 

 Fruit capsular or naked granulation's. Fronds filiform a.nd geniculate, con- 



' The peristomt is (he membrane vvhicli appears around the mouth of the capsule of 

 under the lid 



