Ser. CHLOROSPERMU&. Fam. Confervee. 
Puate CCXXXVIII. 
RHIZOCLONIUM* RIPARIUM, Adz. 
Gen. Cuar. Filaments green, jomted, uniform, decumbent, simple or 
spuriously branched; branches short and root-like. Fruit, granules 
contained in the cells. Ru1zoctontum (Kiitz.),—from pifow, to root, 
and kro, a branch. 
Ruizoctontum riparium ; filaments long, slender, decumbent, pale-green, 
forming wide strata, flaccid, entangled, angularly bent, furnished at 
the angles with short, root-lke processes (which sometimes, but 
rarely, lengthen into very patent branches, and often attach them- 
selves to neighbouring filaments.) 
Ruizoctonivum obtusangulum, Kitz. Phyc. Gen. p. 261. (and probably R. Jur- 
gensit and R. littoreum, 2b.) 
ConFeRva riparia, Roth Cat. Bot. vol. ii. p. 216. Eng. Bot. t. 2100. Dillw. 
Conf. p.111. Sup.t. HE. Ag. Syst. p.106. Harv. in Hook. Br. Fl. vol. ii. 
p. 359. Harv. in Mack. Fl. Hib. part 3. p. 230. Harv. Man. p. 140. 
Conrerva obtusangula, Lyngb. Hyd. Dan. p. 159. t. 55. 
ConFeErkva perreptans, Carm. Harv. in Hook. Br. Fl. vol. ii. p. 352. 
ConFrerva tortuosa, Wyatt, Alg. Danm. no. 190. (not of Dillw.) 
ZYGNEMA littoreum, Lyngb. Hyd. Dan. t. 59. (?) 
Has. On sand-covered rocks, near high-water mark. Annual. Summer. 
Not common. Bantry Bay, Miss Hutchins. Sunderland, Mr. W. 
Backhouse. Yarmouth, Mr. Dillwyn. Torquay, &e., Mrs. Griffiths. 
Appin, Capt. Carmichael. 
Geogr. Distr. Shores of Northern Europe. 
Descr. Filaments prostrate, forming pale green strata, sometimes spreading in 
patches some square feet in area, slender, lying close together, and fre- 
quently matted inextricably. The threads are angularly bent at intervals, 
and from each angle issues a short, root-like tapering ramulus, usually 
consisting of two or three cells, standing at right, or very obtuse angles 
with the main filament. This rarely lengthens into a proper branch: more 
generally it preserves the root-like character, and attaches itself to a neigh- 
houring filament, and sometimes two such rootlets uniting together, bind the 
filaments still more closely together. I have not observed the roots inoscu- 
lating with the attached filament, as the connecting tubes of Zygnema do. 
Articulations about twice as long as broad, full of a pale-er een endochrome. 
Substance flaccid, not very closely adhering to paper. 
This curious little plant was first noticed as British by the 
* Misprinted Rhizogonium in the systematic index to the 1st volume. 
