CONFERVA. 207 



Harv. 1. c. p. 359 ; Harv. Phyc. Brit. t. ccxxxviii . Cow/. 

 tortuosa, Wyatt, Alg. Damn. No. 190, (not of Dillw.} 



On sand-covered rocks, near high-water mark, not uncommon. Form- 

 ing decumbent, dense strata of some extent. Filaments very slender, 

 with a few root-like branches below, and once or twice branched above. 

 Colour light green, much paler and without gloss when dry. Conf. per- 

 reptans, Carm., is either this species, or a closely allied form. 



III. CONFERVA. Plin. [Plate 24, E.] 



Filaments green, attached or floating, unbranched, com- 

 posed of a single series of cells or articulations. Fruit 

 aggregated granules or zoospores, contained in the articula- 

 tions, having, at some period, a proper ciliary motion. 

 Name, from confer ruminare, to consolidate, because some 

 of the species were used by the ancients for binding up frac- 

 tured limbs. This genus, notwithstanding the weeding which 

 it has received of late, requires to be still further dismem- 

 bered, when the species shall have been carefully observed at 

 all ages. Generic characters will probably be found in the 

 different manner in which the endochrome is matured, and 

 the manner in which new cells are formed. 



* Filaments decumbent, stratified, either unattached, or soon becoming 

 so, and at length floating. 



1. C. arenicola, Berk.; threads soft, simple, extremely 

 fine, matted, somewhat crisped, at first uniform pale green, 

 at length distinctly jointed; articulations once and a half as 

 long as broad, dotted ; interstices pellucid. Berk. Gl. Alg. 

 t. 13, /. 3. 



" Creeping on the sandy margins of pools in a salt-marsh periodically 

 flooded, forming a thin, soft, delicate, crisped web, of a pale yellow-green. 

 Threads extremely slender, flexuous, at first self-coloured with a few scat- 

 tered dots, then with manifest dissepiments, and finally the granules con- 

 tract and form a distinctly defined mass of a darker green in the centre, 

 with pellucid interstices. When dry the articulations are slightly con- 

 tracted." Rev. M. J. Berkeley. 



2. C. arenosa, Carm.; filaments slender, rigid, interwoven 

 into broad strata ; articulations 3 5 times longer than broad. 

 Harv. I. c. p. 353. 



On the flat sandy shore about half-tide level. Appin, dipt. Carmichael. 

 Bantry Bay, Mr. R. Ball. " This species occurs in fleeces a yard or more 

 in extent, and of a peculiar structure. They consist of several exceedingly 

 thin layers, placed over each other; but so slightly connected that they may 

 be separated like folds of gauze, to the extent of many inches, without the 



