Plate LXXI. 



Fig. 332. ENTEROMORPHA ERECTA. 



Colour. A pleasant^ liglit grass-green. 

 Substance. Membranaceous; thin; soft. 



Character of Froiid. Tliread-like (filamentous)} cylindrical; tubular; rising 

 with a (generally) undivided main stem^ closely set with, opposite or 

 alternate undivided branches; the lowermost longest; all tapering at 

 the tips. Branches clothed throughout with short, slender, almost 

 hair-like, spreading branchlets, which give the plant a feathery ap- 

 pearance. All the tips finely pointed. 



Measurement. From 4 to 8 inches long. 



Fructification. Minute seeds [zoospores) formed of the colouring matter in 

 the cells of which the frond-membrane is composed; and in due 

 time bursting through them. 



Habitat. Our coasts generally. On rocks and in pools between tide-marks. 

 Not uncommon. 



The above description applies to the strictly characteristic specimens of the 

 species; so called typical forms, that is. Bat intermediate ones abound, which 

 are neither exactly erecta, nor yet JE. clathrata, ramulosa, or Linhiana, but 

 combinations from them; and Dr. Harvey is of opinion that these four species 

 are but one, under different circumstances of growth. For the present, how- 

 ever, the variations take rank as typical characters; and all that a collector 

 can do, is to place his intermediates in the set they come nearest to, on the 

 whole. He cannot go far wrong so long as he keeps those with pointed tips 

 clear of those with blunt ones. In the Nereis Boreali- Americana, E. erecta 

 and E. ramulosa are referred to E. clathrata. 



Fig. 333. ENTEROMORPHA CLATHRATA. 



Colour. A delicate grass-green. 

 Substance. Membranaceous; thin; soft. 



Character of Frond. Thread-like {filamentous)', cylindrical; tubular; bushy; 

 rising with a (generally) undivided main stem, closely set with 

 branches on every side; all tapering to the tips; occasionally inter- 

 woven and spreading in fleeces. Branches several times re-branched; 

 everywhere thickly clothed with short, hair-like, wide-spread, or 

 back-curved branchlets. All the tips finely pointed. 



Measurement. From 2 to 12 inches long. 



Fructification. As before. 



Habitat. Our coasts generally. On rocks between tide-marks. Not un- 

 common. 



Distinguished from ramnlosahy its greater slenderness, softness, and more 

 profuse branching. 



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