226 LYNGBYA. 



* Filaments perfectly continuous; endochrome cylindrical, imperfectly 

 annulated. 



1. L. majuscula, Dillw. ; filaments very thick, issuing in 

 long, crisped bundles from a blackish green stratum, tortuous, 

 simple or slightly pseudo-branched. Harv. I. c. p. 370 ; 

 Wyatt, Alg. Danm. No. 147; Harv. Phyc. Brit. t. Ixii. 

 Conf. majuscula, Dillw. Conf. t. A. 



Thrown up by the sea. Santon Sands, Miss Hill. Bantry Bay, Miss 

 Hutchins. Torbay, Miss Griffiths. Belfast Bay. Dr. Drummond. Port- 

 rush, Mr. D. Moore. Filaments forming blackish green, interwoven strata, 

 from which they issue in crisped bundles, 1 or 2 inches long, very tortuous, 

 simple, or occasionally agglutinated together so as to appear branched. 

 Diameter greater than that of any of the genus, twice or thrice as great as 

 that of L. muralis. Endochrome dull green, annul! difficult to observe, 

 close set; border of the tube broad and colourless. A fine species, errone- 

 ously referred by Agardh to his L. crispa, which, according to an authentic 

 specimen, is a very different plant, of a verdigris-green colour, and thrice 

 as slender. 



2. L. ferruginea, Ag. ; filaments slender, flaccid, forming 

 a lax stratum, of a verdigris-green colour, which gradually 

 changes to a pale chesnut. Harv. I. c. p. 370. L. ferru- 

 ginea, ft. versicolor, Ag. Syst. p. 73. L. sulsalsa, Carm. MS. 



In small mud-bottomed pools by the sea-side, filled at spring-tides. Ap- 

 pin, Capt. Carmichael. " Stratum exceedingly thin and lax, extensive, at 

 first of a vivid green colour, but passing gradually into a pale chesnut." 

 Carm. Filaments an inch long, flaccid, bent in various curves but scarcely 

 tortuous, of a pale verdigris colour under the microscope; striae rather evi- 

 dent and subdistant. Capt. Carmichael's plant is of a dull verdigris hue, 

 without gloss. I have compared it with an authentic specimen from 

 Agardh, and can detect no difference, except in colour, which, according to 

 Carmichael, varies with the age of the individual. Agardh's j3. appears to 

 answer to the British plant very exactly. 



** Filaments imperfectly articulated ; endochrome distinctly annulated, se- 

 parating into lenticular articulations, with pellucid dissepiments. 



3. L. Carmichaelii, Harv. ; filaments very long, thickish, 

 curled and tortuous, cylindrical, floating under water, and 

 forming extensive, grass-green strata. Harv. L c. p. 371 ; 

 Harv. Phyc. Brit. t. clxxxvi. A. L. crispa, Carm. MSS. 

 cum icone (not of Agardh) ; Wyatt, Alg. Danm. No. 230. 



On marine rocks and Fuci. Appin, Capt. Carmichael. Plymouth and 

 Torbay. Mrs. Wyatt. Cornwall and Anglesea, Mr. Ralfs. Coast of Ire- 

 land. " Stratum almost co-extensive with the object on which it grows. 

 On Fucus vesiculosus it may be found upwards of a foot in extent, on the 

 rocks, of 20 30 yards, covering them with an intensely green fleece. Fi- 

 laments fixed at the base, but fluctuating freely with the agitation of the 



