258 NEMATOGENA. 



Lyngbya aestuarii. Lieb. Danska Alg flora. (1839.) 



Trichomes rigid, flexuously curved, blue green, granular, 

 densely interwoven in dark blue green tufts ; joints 3-6 times 

 shorter than their diameter ; scarcely constricted ; sheaths 

 pellucid, hyaline, becoming brownish, at first scarcely larnellose, 

 at length when old becoming distinctly lamellose. 



SIZE. Trichomes '025--03 mm. diam., without sheath. 



Lyngbya ceruginosa, Ag. Syst. p. 74. Rabh. Alg. Eur. ii., 

 138. 



Lyngbya ft. ferruginea, Harv. Phyc. Britt., t. 311. 



Lyngbya curvata, Rabh. Alg. Eur. ii., 137. 



Lyngbya majuscula, Cocks Brit. Seaweeds No. 365. 



In brackish water. 



Plate CL fiff. 1. a, portion of filament X 160 diam. J, extremity 

 of filament, with portion of trichome escaped X 160 diam. c, portion of 

 filament with the trichome divided into hormogones X 330. d, e, hormo- 

 gones X 330, all after Thuret. 



Lyngbya littoralis. (Carm). 



Stratum thin, submembranaceons, mucilaginous, blue green, 

 shortly radiating ; trichomes rigid, flexuous, vividly oscillating, 

 equal ; joints 4-5 times as broad as long, constricted at their 

 junction and hyaline, dissepiments granulated, extreme apiculus 

 straight, broadly rounded, paler ; cell contents pale blue green, 

 very delicately granular. 



SIZE. Threads '013--015 mm. diam. 



Oscillatoria littoralis, Carm. Alg. App. ; Eng. Fl. v., 375. 

 Harv. Man., 165. Harv. Phyc. Britt. t. 105, fig. a. 



In brackish water, and in rock pools by the shore. 



" Stratum exceedingly thin, slimy, bullated by the extrication of air- 

 bubbles, of a dark green colour, spreading to an indefinite extent over 

 the muddy bottom of the pool." Carm. 



Plate Gil. Jig. 1. Portions of trichomes X 400, from the original 

 specimens. 



Lyngbya ochracea. Thur. Ann. Sci. Nat. (1875) 377. 



Forming cloud-like floating fragile masses of an ochrey 

 colour. Trichomes very slender, scattered ; joints scarcely 

 visible. 



SIZE. Trichomes '002 mm. diam., including sheath. 



Kirch. Alg. Schl. 241. 



Leptothrix ocliracca, Kutz. Tab. Phyc. i., t. 61, fig. 1. 



Conferva ochracea, Dillw. Conf. t. 62. 



