Ser. RHopOSPERME. Fam. Ceramiee. 
Pratt CCLXXXI. 
GRIFFITHSIA BARBATA, «4. 
Gen. Cuar. Frond rose-red, filamentous ; filaments jomted throughout, 
mostly dichotomous ; ramuli single-tubed; dissepiments hyaline. Fruc- 
tification of two kinds, on distinct individuals: 1, ¢etraspores affixed 
to whorled involucral ramuli: 2, gelatinous receptacles (favella), 
surrounded by an involucre, and containing a mass of minute angular 
spores. GRirFITtHs1a—so named by Agardh, in honour of Mrs. Grif- 
fiths of Torquay, the most distinguished of British Algologists. 
GrifFitHsia Garbata; filaments dichotomous, slender; articulations 
slightly pynform, from five to eight times longer than broad, those 
near the apices of the branches emitting opposite or whorled, byssoid, 
dichotomous fibres (or ramuli) to which the tetraspores are attached ; 
favellee stalked. 
GrirFitusia barbata, 4. Syst. p. 145. dg. Sp. Alg. vol. ii. p. 132. Harv. 
in Hook. Br. Fl. vol. ii. p. 338. Harv. Man. ed.1. p. 102. Kiitz. Sp. p. 660. 
ConFERVA barbata, #. Bot. t. 1814. 
Has. Parasitical on the smaller Algz, in tide-pools. Annual. Summer. 
Very rare, and seemingly confined to the coasts of the British Channel. 
Beach at Brighton, Mr. Borrer. Jersey, Miss Turner. 
Goer. Distr. North coast of France; not uncommon in old oyster-beds, at- 
tached to the shells and to small stones, Lenormand. 
Descr. Fronds one to three inches high, as thick as hog’s bristle below, capillary 
and byssoid above, forming dense, fastigiate tufts, repeatedly and pretty re- 
gularly dichotomous ; the lower axils rather distant and patent, the upper 
close together and very acute. All the lower part of the frond is bare of ra- 
muli; butthe articulations of the terminal ramuli give off throughout from their 
apices, opposite, or whorled, very slender, byssoid, dichotomous, spreading 
ramelli. Articulations from five to eight times as long as broad, slightly 
swollen upwards, or nearly cylindrical. Favelle pedunculate, formed out 
of truncate branches, binate, surrounded by numerous, simple or forked, 
involucral ramuli. Tetraspores spherical, attached to the byssoid fibres 
that issue from the upper articulations, one tetraspore generally on each 
dichotomous fibre. Colour a fine, clear rose-red, changing to orange in 
fresh water. Substance tender and lubricous, most closely adhering to 
paper in drying. 
1 am indebted to Miss Turner, of Jersey, for beautiful speci- 
mens of this exceedingly rare plant, with both kinds of fructifi- 
cation—from some of which specimens the figure here offered 
