294 BRITISH SEA-WEEDS. 



Actinothrix Stokesiana. Mrs. Stokes's Actino- 

 thrix. 



" Klaments bright green, about a quarter of au inch long, 

 growing nineteen or twenty from one centre ; endochrome 

 surrounded by a transparent margin." 



The specinaens 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 Lyngbya majuscula, at West Cowes. 



Order XXV. NOSTOCHINE^. 



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

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

 formed of globose cells, here and there interrupted ly a 

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

 gation hy 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. — Monoe- 

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



Monormia intricata. The intricate Monormia. 



IVonds " forming small, roundish, gelatinous masses, 

 floating among Lemna in fresh water, hut probably within 

 the influence of the tide ; and also amongst lEnteromorpha 

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



Genus CXXIX. SPHJEROZYGA. 



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- 



