Fig. 101. RYTIPHLCEA THUYOIDES. 
Colour. A dull-brown or brownish-yellow ; becoming black in drying. 
Substance. Eobust and elastic. 
Character of Frond. Thread-like {filamentous)'., tufted; branched; the filaments opaque, 
closely marked with lines across {transversely striate). Stems thread-shaped {filiform ) ; 
erect ; rising from creeping fibres ; below, naked ; or set with short spine-like branch- 
lets ; above, much branched ; branches close, very erect, many times re-branched, 
but shortly, so as always to preserve a narrow lanceolate outline. 
Measurement. From 3 to 4 inches long. 
Fructification. Of two kinds. 1. Clusters of spores in ovate capsules; external. 2. Teira- 
spores in distorted swollen branchlets. 
Habitat Our coasts generally. In tide-pools, frequent ; but not on the N. East coast. 
Fig. 102. RYTIPHLCEA FRUTICULOSA. 
Colour. Dull reddish, or yellowish-brown. 
Substance. Eobust and elastic. 
Character of Frond. Thread-like {filamentous)'., tufted; branched; the filaments opaque, 
closely marked with lines across {transversely striate). Stems forked (spreading 
widely) from the base ; branches the same, partly forked {dichotomous), partly branched 
like a feather {pinnate). Angles of the branches {axils) rounded. Branchlets alter- 
nate ; horizontal ; short ; so that each branch has a narrowish outline. 
Measurement. From 3 to 6 inches long. 
Fructification. Of two kinds. 1. Clusters of spores in ovate capsules; external (very rare). 
2. Tetraspores in swollen branchlets (common). 
Habitat. Our coasts generally. On sand-covered rocks between tide-marks. Common. 
For the other Rytiphlceas, see Plate XXIV. Fig. 104 ; and Plate XXV. Fig. 108. 
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