Plate LXVIII. 
Fig. 318. EHIZOCLONIUM CASPAEYI. 
Colour. Light, bright yellow-green ; fading very dull in the herbarium. 
Substance. Soft and delicately woolly ; a peculiarity it retains in the herbarium. 
Character of Frond. Long, very slender, jointed threads {filaments') lying flat on the sides of 
rocks, clothing them with a fine close fleece. Filaments entangled, curved, here and 
there angularly bent ; and sending out from the angles short, horizontal, thorn-like, 
jointed, colourless fibres, which sometimes lengthen into true branchlets, containing 
colouring matter {endochrome). 
Joints. From two to six times longer than broad. 
Measurement. From 1 to 3 inches long. 
Fructification. Minute seeds {zoospores) formed of the colouring matter in the joints, and in 
due time bursting through them. 
Habitat. Falmouth and Penzance. 
It will be seen, by comparing the descriptions, tbat except in the greater slenderness of 
the threads, and occasionally greater length of the joints, there is no difference between this 
plant and R. riparium. And Dr. Harvey says that joints of different lengths are sometimes 
found even on the same threads. 
Fig. 319. CONFERVA TORTUOSA. 
Colour, Pale, full, or dark green, in different specimens. 
Substance. Eigid. 
Character of Frond. Slender, closely-interwoven, jointed threads {filaments) ; forming a fleecy 
web upon rocks or algse. Filaments about the thickness of horse-hair ; very much 
and stiffly curled and twisted ; unbranched. 
Joints. Twice or thrice longer than broad ; filled with green colouring matter {endochrome). 
Measurement. The fleecy web from an inch to several feet in diameter. 
Fructification. As before in Rhizoclonium (and Cladophora). See under Fig. 318. 
Habitat. Our shores generally. On rocks and algte at half-tide level. Very common. 
Fig. 320. CONFERVA IMPLEXA. 
Colour. Bright green. 
Substance. Soft and delicate. 
Character of Frond. Very slender, densely-interwoven, jointed threads ; forming a fleecy web 
upon rocks ; or little tufts among the branches of other algse. Filaments as fine as 
human hair (half the thickness of C. tortuosa) ; entangled, but not stiffly twisted ; 
unbranched. 
Joints. About as long as broad ; or a trifle longer. 
Measurement. Indefinite, from half an inch to a foot. 
Fructification. As before. 
Habitat. Our coasts generally. On rocks and alg^ between tide-marks. Not uncommon. 
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