344 
CLASS XXI. ORDER V. 
receptacle is elevated one or two inches by a stipe attached to the centre 
of its lower side, among the capsules and many pilose appendages. The 
frond is leafy, reticulate, furnished with a midrib, and beset with villose 
roots on the under side, which attach themselves to the stones in brooks, 
to damp earth, &c. 57. 3. 
Jungerman"jvia. 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. 57. 3. 
Order 4. oilgas. 
A. The section Fucoidea; comprises those sea-weeds 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 interwoven 
longitudinal fibres. The floating vesicles appear like portions of the 
frond blown up in bubbles. 
Focus. Receptacles tubercled ; tubercles perforated, nourishing ag- 
gregated capsules within, intermixed with articulated fibres. 57. 2. 
B. The section Florideae comprises those sea^weeds of the old genus Fu- 
cus , whose fronds are leathery , membranous or gelatinous , and of a 
purple or rose colour. 
Halyme'nia. Frond membranaceous, leathery, nerveless, punctate : 
seed immersed throughout the whole frond, disposed in spots. 57. 2. 
C. The sections Ulvoidea; comprises the plants of the old genus TJlva. 
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. They grow on rocks, stones, shells, &c. in the sea ; also in ditches, 
stagnant waters, damp woods, &c. 57. 2. 
Ulva. Seeds in fours, immersed in every part of the membranaceous 
frond. 57. 2. 
D. The sections Coxfervoide.® comprises the plants of the old genus Confer- 
va. Fruit capsular or naked granulations. Fronds filiform and genicu- 
late, containing the fruit immersed in them, generally strung on threads ; 
mostly of a grass-green or greenish colour, sometimes purple. They grow 
in fresh water streams, "springs, ditches, and stagnant waters ; sometimes 
in damp woods, and some in the sea. 
Confee"va, Filaments articulated, uniform, simple or branched ; contain- 
ing the seed within them. No external fruit. 57. 2. 
E. The section Tremellinje comprises the old genus Tremella. Plants of 
this section are all gelatinous, hyaline, and covered with a membrane. They 
are globose, palmate, or filiform ; and contain conferva-like filaments with- 
in. Colour green or purplish. They resemble Canfcrvoideae in habit and 
place of growth. 
Nostoc. Filaments monili-form, constituted from coadunate globules. 
Frond bullate, vesicular, (at length becoming flattened,) crowded with simple 
monili-form, curve-crisped filaments. 57. 2. 
Order 5. Lichenes. 
Gyroph'ora. Frond foliaceous, coriaceous-cartilaginous, peltate, mono- 
phyllous, (when luxuriant, polyphyllous,) free beneath : receptacles (but- 
tons) somewhat shield-form, sessile-adnate, clothed with a dark membra- 
naceous cartilage, including a somewhat solid parenchymous substance ; 
disk warty or circinal, plicate and margined. 57. 2. 
Parme'liA. Frond coriaceous , sub-membranaceous, flat, expanded, 
closepressed, orbicular, stellate and lobed, or multifid-laciniate, having 
fibres beneath : receptacle shield-form, sub-membranaceous, formed un- 
