,a'i
J..':-, ii i
i / / k>h
Ui '! A - I
\i ilr ' ....
‘f !<
1- ■ î"
, ii;
I)
Plate X L Y lll.,J ig s . 6.7. Oogonia and antheridia of V. geminata X
200. Fig. 8, non-sexual spores of the same X 200, after Walz. Fig. 9,
mature oospore x 200.
Plate \XL1X., fig. i, fruiting branch of the variety racemosa, after
Hassall.
7 . Vaucheria hama ta . (Vauch.) Walz. p. 148, t. XII./, 12-17.
Aqnatio or terrestrial, thallua rather rigid, vaguely branched.
Oogonia usually single, ovate or ovate-hemisphEerioal, seated
on a short segment of the divided stem, the other segment
elongated, curved, forming the antheridium. Mature oospores
involved in a sporoderm formed of four or more strata.
Cleve Vaucb. p. 6. Hassall Alg. t. v., f. 1. Gray Arr. i.,
289.
Ectosperma hamata, Vauch. Conf. 26, t. 2, f. 2. Hass.
Ann. Nat. Hist. x i.,p . 489.
Vaucheria hamulata, Kutz. Tab. Phyc, vi., t. 61, f. 2.
In ditches.
V aucher wrote of this species—“ It differs from all others by the
manner in which it carries its grains. The peduncles which sustain them
are much elongated, and they hear at their extremity two little threads,
the one is recurved and receives the anther, the other is shorter and
straighter, and carries the grain.’’
Plate XLVIII.,figs. 10, 11. Oogonia and antheridia of F. hamata X
200. Figs. 12, 13, mature oospores free from oogonia x 200. Fig. 14,
sporangium X 200.
8 . Vaucheria te r r e str is. Lyngh. Hydro. Ban. p. 77, t. 21, f. A.
Densely interwoven in a thin bright emerald stratum.
Oogonia usually single, pedunculate, attached by the flattened
base at tbe back of the incumbent elongated curved antheridium.
Mature oospores enclosed in a hyaline colourless sporoderm
composed of four strata, considerably inflated.
Eng. Flora v., 320. Grev. Alg. Britt, p. 191. Eng. Bot.
ii., p. 124. Jenner Tunb. Wells, 176. Harv. Man. 148.
Jobnst. FI. Berw. ii., 251. Mack. Hib. 234. Gray Arr. i.,
290. Hass. Alg. 53, t. 5, f. 2. Berk, Glean, t. 9. Walz.
Jahrb. p. 149, t. xiii., f. 18, 19. Eabh. Alg. F u r. p. 270.
Cleve Vauch. 131, f. 1.
Ectosperma terrestris, Vaucb. p. 27, t. 2, f. 3.
Vaucheria circinata, Kutz. Tab. vi., t. 60, fig. 2.
Forming patches on damp and clayey soil.
“ Threads more straight and rigid than in V. Bilhvyni, forming a more
lax and less interwoven stratum, the summits of the little branches often
erect, and giving the whole a bristly appearance.”— Qremlle.
Plate XLIX.figs. 1, 2. Oogonium and antheridium of V. terrestris X
200. Fig. 3, mature oospore of same, after Walz x 230.
Plate XLIX.,fig. 7. Oogonium of F, velutina, A s. (a marine species),
after Harvey X 200. P L
Multicellular algæ, chlorophyllose, membranaceous or filamentous,
witb or without branches. Vegetation either terminal,
limited or unlimited, forming an articulate thread, or in tbe
beginning terminal, and afterwards lateral, forming a membranaceous
tballus of a single stratum. Cell multiplication by
repeated division in one or two directions.
Propagation by oospores, or by zoogonidia.
Divided into the following families
A. Vegetation by division of the cells at first in one, and
afterwards in two directions, forming a membranaceous thallus.
F amily I. U lvaoeæ.—Thallus membranaceous formed of one
stratum of cells, eitber plane or expanded, or tubular, or saccate.
B. Vegetation by division of the cells in one direction,
forming a cellular series or articulate thread.
F amily I I .— S phæ ro p lbæ .—Articulate thread not branched,
articulations greatly elongated, cylindrical, multilooular, chlorophyll
mass distributed in ring-like bands.
Propagation by resting spores, which, before germination,
break up into zoospores.
F amily I I I . C onpbevaoeæ.— Articulate thread, simple or
branched, vegetative articulations cylindrical, fructiferous always
more or less swollen. Chlorophyllose mass effused, or parietal,
often more or less regularly spiral.
Propagation by macro- and mioro-gonidia.
F amily IV . P ithophoraoeæ.— Cladophora-like plants,
with terminal vegetation. Articulate threads branched.
Propagation by neutral, quiescent, cask-shaped spores
(agamo-hypnospores). . . , -.a
F amily V. OE dogoniaobæ.—Articulate thread either
branched or not branched ; articulations short.
Propagation by oospores after sexual fecundation.
F amily VI. U lotrioheæ.—Articulate thread not branched,
sometimes laterally connate ; articulations short, at times very
short.
Propagation by macro- and mioro-gonidia.
F amily V II. Oheoolbpidæ.— Aërial algæ. Articulate
thread branched, cell membrane firm, filled with an equally distributed
oleaginous golden or reddish endochrome.
Propagation by zoogonidia. * • , ,
F amily V I I I . Chætophoeeæ .—Aquatic algæ. Articulate
thread dichotomously branched, ramuli sometimes aggregated in
a fasciculate or penicellate manner. Chlorophyllose mass
usually collected in transverse bands.
Propagation by zoogonidia.—Rabh. Alg. Eur. iii, 286.