IY. 
SPOROCITNACEiE. — Chnoospora. 
79 
“ Frond flat, two feet or more long, rising with a single, undivided stem , at its 
base nearly cylindrical, and as thick as a crow’s quill, but almost immediately 
becoming flat, and gradually widening to the height of a few inches, where it 
acquires a width of half an inch, or three quarters of an inch, after which it 
becomes linear, till, on approaching the extremity, it is again slightly narrowed 
and terminates in a rounded apex ; the margins are throughout the whole length 
serrated with small, spiniform, rather remote teeth ; the stem, from root to summit, 
is pinnate with opposite, distichous branches, of the same substance as itself, between 
horizontal and patent, separated by intervals of about half an inch, a foot or a foot 
and half long, and the middle ones, apparently, longest, their greatest width nearly 
an inch, attenuated at their bases into very short, subcylindrical petioli, rounded at 
their apices, toothed at their margins, and in their turns pinnated with a series of 
others, similar to them in every particular, except their small size : — throughout 
the whole frond runs a midrib, thick and rather wide in the stem, but in the 
branches thin and faint, so as scarcely to be visible, unless the plant is held to the 
light, and appearing only like a dark line. Colour grass-green, with a faint tinge 
of brown, transparent. Substance membranaceous, extremely thin and tender, but 
somewhat thickened in the stem, near the root.” 
I have not seen any American individuals of this variety, but have gathered an 
equally broad-leaved form at the Cape of Good Hope, having, however, acute pinnae, 
and a firmer and more coriaceous substance than Turner describes. On the whole 
I agree with Prof. J. Agardh in uniting, as one species, the broad leaved and nar- 
row leaved forms. 
III. CHNOOSPORA, J. Ag. 
Froncl compressed, repeatedly dichotomous, ribless ; its substance composed of 
elongate prismatic cellules, scarcely denser in the centre. Fructification , densely 
tufted, clavato-moniliform, articulated, spore-bearing filaments, surrounded by 
sterile, branching filaments ( paranemata) , both aggregated together in wartlike 
excrescences near the middle of the frond. Spores (?) formed in the articulations 
of the sporiferous filaments, rounded. — (J. Ag.) 
A small genus of tropical Algas, readily known by its dichotomous branching. 
It seems to connect together, naturally, the two sub-orders of which the Order 
consists. In the structure of its masses of fructification there is an evident passage 
between those genera with dispersed spore-filaments and those in which these organs 
cohere together into definite receptacles. 
1. Chnoospora fastigiata, J. Ag. ; “fronds tufted, several rising from the same 
