Plate XLVI. 



Fig. 209. DUMONTIA FILIFOEMIS. 



Colour. Dull purple; fading to green and yellow. 



Suhstance. Gelatinous; membranaceous; tender; very slippery to tlie toucli. 



Character of Frond. A simple stem^ finely drawn out and tapering to each end 

 [attenuated); furnished with long, simple, alternate branches, attenuated 

 in the same manner. Both stem and branches cylindrical and tubular; 

 filled with a watery jelly. 



Measurement. Stem sometimes from 8 to 18 inches long, with branches 

 from 4 to 5. In other specimens the stem is very short (from 2 

 to 3 inches); and the branches from 10 to 14. In others there 

 is scarcely any stem at all. In others the whole plant is small and 

 thead-like [iilainentous) . 



Fructification. Of two kinds. 1. Roundish masses of spores (favellce) 

 immersed in the substance of the frond. 2. Tetraspores imbedded 

 beneath the same; scattered over the branches. Visible like dark 

 dots through. 



Habitat. Our coasts generally. On rocks, &c. at half-tide level. Cotnmon. 



Fig. 210. NEMALEON MULTIFIDUM. 



Colour. Dull purple^ or purplish-brown. 

 Substance. Gelatinous; solid; very elastic; firm. 



Character of Frond. Cylindrical, about the thickness of a crowds quill; * 

 once or twice forked, distantly; or simple; or irregularly, slightly 

 branched. Axils rounded and clumsy. 



Measurement. From 3 to 6 inches long. 



Fructification. Only one kind known. Globular masses of spores attached 

 to the filaments which form the outer layer of the frond. Visible 

 like dark dots through. 



Habitat. Our coasts generally in the warmer stations. Common along 



the western shores of Scotland and Ireland. On rocks and shells 

 near low- water mark in exposed situations. Not unfrequent. 



17 * D • 



