cryptonemiacejE. 195 



forked, necklace-like, horizontal branches, whose tips, joined 

 together with gelatine, form the outer wall of the frond. 

 Spores in nuclei among the axile filaments of small, roundish, 

 subsidiary branchlets. — Catenella, from the Latin catenula, 

 a little chain. 



A genus containing very few species of small insig- 

 nificant plants, of which one only is a native of Great 

 Britain. 



Catenella opuntia. The cactus-like Catenella. 



Fronds erect, from half an inch to an inch high, densely 

 tufted, slightly branched, springing from a mass of creeping 

 fibres ; branches alternate or opposite, constricted, simple 

 or forked, with pointed tips. Spores in round masses, con- 

 tained in egg-shaped conceptacles with a terminal pore ; 

 tetraspores zonate, formed from the outer threads of the 

 frond, and scattered among them. 



Unlike most of its allies, this little plant is generally 

 found on rocks which are not long submerged. It forms 

 patches of two or more inches in diameter, and resem- 

 bles slightly the young plants of Chylocladia articulata, 

 but it may be readily distinguished by its darker colour 

 and drier texture. It is perennial and not uncommon, 

 but is rarely found in fruit. 



Genus XCI. G-LOIOSIPHONIA. 



Frond very gelatinous, much branched, composed of an 

 axis of interwoven jointed filaments, which form a longitu- 

 dinal column at first, and subsequently a tube, and a peri- 

 phery of numerous, whorled, necklace-like, forked filaments, 

 set in gelatine. Spores numerous, enveloped in a gelatinous 

 membrane, and immersed in clusters (favellse) beneath the 



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