294 BRITISH SEA-WEEDS. 



Actinothrix Stokesiana. Mrs. Stokes's Actino- 

 thrix. 



" Filaments bright green, about a quarter of an inch long, 

 growing nineteen or twenty from one centre ; endochrome 

 surrounded by a transparent margin." 



The specimens on which this genus and species are 

 founded were collected by Mrs. Stokes, floating among 

 Cladophorce, in Dingle Bay, Ireland. Others have since 

 been found on Lynghya majuscula, at West Cowes. 



Order XXV. NOSTOCHINE^. 



Green, freshwater or rarely marine Algce, composed of neck- 

 lace-like threads, lying in a gelatinous matrix. Threads 

 formed of globose cells, here and there interrupted by a 

 single cell (heterocyst) of a different character. Propa- 

 gation by zoospores. 



Genus CXXVIII. MONORMIA. 



Frond a branched mass of loose-textured gelatine, con- 

 taining a spiral, necklace-like string of spherical, coloured, 

 ordinary cells, with here and there a connecting-cell of larger 

 size. Zoospores developed from the ordinary cells. — Monor- 

 mia, from the Greek monos, one, and hormos, a necklace. 



Monormia intricata. The intricate Monormia. 



Fronds " forming small, roundish, gelatinous masses, 

 floating among Lemna in fresh water, but probably within 

 the influence of the tide ; and also amongst Enteromorpha 

 intestinalis, and even within its frond, in brackish water." 



Genus CXXIX. SPHJ3ROZYGA. 



Frond a gelatinous layer, or skin containing simple, neck- 

 lace-like, waved or curved threads, composed of a series of 

 ordinary cells, with connecting-cells of a different kind, usu- 



