332 BRITISH SEA-WEEDS. \Cliloros]iermece, 



Genus XCYII. CALOTHHIX, Agardh. 



Gen. Char. Filaments destitute of a mucous layer, erect, 

 tufted or fasciculate, fixed at the base, somewhat rigid, without 

 oscillation. Tube continuous; endochrome green, densely an- 

 nulated, at length dissolved into lenticular sporidia. — The name 

 signifying heaut'ifiil hab\ the filaments being very slender and 

 delicate. — Harvey. 



1. Calothrix conferyicola, Agardh. 



Hab. On marine Algae. 



This is very common on sea-\Yeeds of the smaller kinds, 

 giving them a bluish-green hue, only a line or two high, 

 and forming scattered or continuous tufts. There are up- 

 wards of a dozen species of Calothrix, some of which are 

 rare, and some are found in fresh water. See Phyc. Brit., 



PI. LVIII., LXXYI. 



Genus XCYIII. EIVULAKIA, Both. 



Gen. Char. Proud globose or lobed, rarely increasing, fleshy 

 or gelatinous, firm, composed of continuous inarticulate filaments, 

 annulated within, and surrounded by, or set in, gelatine. — 

 Harvey. — The name is in allusion to the fresh-water habits of 

 many of the species. Many, however, are found in the sea. 



1. RiYULARIA ATRA, lioth. 



