1919] Setchell-Gardner : Myxophyceae 77 



Lyngbya aestuarii f. natans Gomoiit 



Plate 1, fig!. 15 



Plants at first forming- layers on the mud at the bottom of salt 

 mai*sh pools, later floating ; filaments elongated, flexuons or nearly 

 straight and loosely intertwined. 



Floating in pools, salt marsh, Whidbey Island, Washington. 



Gomont, Monogr. des Oscill., 1892, p. 129 (1893, p. 149, Repr.), 

 Setchell and Gardner, Alg. N.W. Amer., 1908, p. 187 ; Collins, Holden 

 and Setchell, Phyc. Bor.-Amer. (Exsicc.), no. 904. 



Lyngbya aestuarii f. spectabilis (Thur.) Gomont 



Sheaths up to 14/a tliiek, hyaline on the exterior, changing to yel- 

 lowish golden color on the interior. 



Growing in salt marsh, Whidbey Island, Washington. 



Gomont, Monogr. des Oscill., 1892, p. 130 (1893, p. 150, Repr.) ; 

 Setchell and Gardner, Alg. N.W. Amer., 1903, p. 187. Lynghjja 

 spectabilis Thuret, in Holmes and Batters, Rev. List Brit. Mar. Alg., 

 1890, p. 68 {fide Gomont, loc. cit.). 



5. Lyngbya confervoides Ag. 



Filaments attached, caespitose, at times twisted into small, rope- 

 like fascicles, mucous, 1-5 era. high, dark olive green or yellowish 

 brown with age ; sheath hj^aline, homogeneous or slightly lamellate, 

 more or less roughened on the surface, 3.5-5/x thick; trichomes olive 

 green or aeruginous, not constricted at the dissepiments, not attenuate, 

 9-25/x, usually 10-1 6/a diam., cells 2-8 times shorter than the diameter ; 

 dissepiments generally granular; terminal cell wall convex, not 

 thickened. 



Growing in shallow rock pools along high-tide level. Central 

 California. 



Agardh, Sp. Alg., 1824, p. 73 ; Gomont, Monogr. des Oscill., 1892, 

 p. 136 (1893, p. 156, Repr.); Collins, Holden and Setchell, Phyc. 

 Bor.-Amer. (Exsicc), no. 2206, as the host of Lyngbya epipliytica 

 Hieron. 



The type localitj^ for the species is Cadiz, Spain, but it is generally 

 recognized as occurring in the warmer water all over the globe. Thus 

 far it has been found only on the central coast of California, l)ut is 

 probably of wider distribution. The specimen distributed under 



