Plate X. 
Fig 37. DICTYOTA DICHOTOMA. 
Colour. Olive ; more or less green or brown. 
Substance. Thin ; semi-transparent ; membranaceous. 
Character of Frond. Flat ; ribless ; narrowish throughout ; branched. Branching, forked 
{dichotomous ) throughout ; the frond becoming narrower upwards. Margins entire. 
Boot woolly. 
Measurement. From 3 to 12 inches long. Width varying from ^ of an inch to an almost 
hair-like fineness. The average width is represented in the figure. 
Fructification. Minute seeds {spores') on both surfaces of the frond ; either in oval clusters or 
irregularly scattered. 
Habitat. Our shores generally. On rocks and sea-plants between tide-marks. Common. 
The narrow variety (D. intricata) is troublesome to lay out; being truly “much branched, 
twisted, and entangled.” 
Fig. 38. STILOPHORA RHIZODES. 
Colour. A greenish olive when young ; when old, foxy brown. 
Substance. Elastic and gristly when fresh, but soon turning soft and gelatinous in fresh 
water. 
Character of Frond. Thread-shaped {filiform) ; solitary or tufted ; branched. Branching irre- 
gular ; mostly forked {dichotomous) ; occasionally alternate. Boot, a disc. 
Measurement. From 6 inches to 2 feet long. 
Fructification. Minute seeds {spores) in convex, wartlike clusters, densely covering the surface 
of the frond, and giving it a dotted appearance. 
Habitat. Shores of England and Ireland, Jersey. Near low water-mark, growing on rocks 
or algae. 
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