Fig. 291. YAUCHERIA SUBMARINA. 



Colour. A bright green. 



Substance. Exceedingly soft and limp. 



Character of Frond. Fine tufts of hair-like threads ^filaments). Filaments not 

 jointed; tubular throughout; filled with green colouring matter, which often 

 runs partially out; repeatedly forked {dicliotomous) . 



Measurement. Two or 3 inches long. 



Fructification. Small, egg-shaped, or lanceolate sacs {sporangia), containing a dark- 

 geen mass, which changes at maturity into minute seeds {zoospores ; so called 

 from having at one period a motion as if endowed with animal life.) 



Halitat. Weymouth. On the muddy sea-shore. Rare. 



Fig. 292. VAUCHERIA VELUTINA. 



Colour. A deeper green than the preceding. 

 Substance. Densely spongy. 



Character of Frond. A mass of tough threads {filaments^ ; forming a velvety car- 

 peting on mud. Filaments creeping; not jointed; tubular throughout; filled 

 with green colouring matter {endochrome') , which often runs partially out; 

 sending up short, upright, simple or forked branchlets, cut to one height, 

 like the pile of clipped velvet. 



Measurement. The mass of green coating indefinite. Branchlets \ of an inch high. 



Fructification. Small, stalked, globose sacs (sporangia), containing a dark-green 

 mass, which, at maturity, is transformed into minute seeds (zoospores; so 

 called from having at one period a motion as if endowed with animal life). 



Halitat. Appin. Miltown Malbay. And on most muddy sea-shores. 



Fig. 293. CLADOPHORA BROWNII. 



Colour. Black-green when growing, but when the water is pressed out, and the 

 plant held to the light, a beautiful yellow-green. 



Substance. Very rigid; spongy. 



Character of Frond. Exceedingly dense, cushion-like tufts of jointed threads (fila- 

 ments) rising from a mass of creeping fibres. Filaments elastic; upright, 

 furnished with a few long, nearly simple, secund branches; so matted together, 

 that it is difficult to separate a single thread. 



Joints. Four or five times longer than broad; the lower ones thickened upwards. 



Measurement. From ^ sua. inch to 1 inch high. 



Fructification. Minute seeds (zoospores; so called from having at one period a 

 motion as if endowed with animal life); formed of the colouring matter in 

 the joints; and in due time bursting through them. 



Hahitat. Cornwall. North of Ireland. Wicklow. On rocks exposed to the drip- 

 ping of fresh water, and the occasional overflow of the sea. 



A plant belonging as much to the land as the sea. 



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