Marine Algae of Berwiok-on-Tweed. 269 



Family— D esmarestiaceae. 



DESMARESTIA, Lamouii. 



Desmarestia viridis (Fl. Dan.) Lamour. 



Ess., p. 25. — Fucus viridis, Fl. Dan., t. 886. 

 Descr. Desmarestia viridis, Harv., Phyc. Brit. 

 Fig. „ „ Harv., I.e. pi. 312. 



Exsicc. Dichloria viridis, Wyatt, Alg. Dainnon., no. 56; Crouan, Alg. 

 Finist., no. 'JO. 

 Desmarestia viridis, Le Jo/., Alg. Mar. Cherb., no. 26. 

 Syn. „ „ Ktz., Spec. Alg., p. 570; he Jot., Liste, p. 71. 



Dichloria viridis, Hook., Br., Fl. II., p. 274; /. .4;/., Spec. Alg. I., 



p. 164. 

 Sporoclmus viridis, Ay., Spec. Alg. i., p. 154 ; Ay., Syst., p. 259. 

 Hub. Cast ashore from deep water. Rare. Berwick Bay, Holy Island. 



The exactly opposite, distichous branches, and the cylindrical 

 or slightly compressed fronds, which turn from olive brown to 

 verdigris green on exposure, or on being placed in fresh water, 

 render Desmarestia viridis unmistakeable amongst British Algae. 



Desmarestia auuleata (Linn.) Lamour. 



Ess., p. 25. — Fucus aculeatus, Linn., Sp. PL, p. 1632. 

 Descr. Desmarestia aculeata, Harv., Phyc. Brit. 

 Fig. „ „ Harv., I.e. pi. 49. 



Et.iicc. „ ,, Wyatt, Alg. Danmon., no. 158; Crouan 



Alg. Finist., nos. 91, 92 et 93 ; Aresch., Alg. Scand. Exsicc. no. 

 87. 

 Syn. „ „ J. Ay., Spec. Alg. i., p. 167 ; Ktz., Spec. 



Alg., p. 571 ; Johnston, Fl. Berwk. n., p. 223: 

 Sporochnus aculeatus, Ay., Spec. Alg. i., p. 151 ; Ay., Syst., p. 259. 

 Desmia aculeata, Lyngb., Hydr. Dan., p. 34, t. 44 b. i. 

 Hab. On rocks at low-water mark and below. All the year. Cast 

 ashore from deep water in considerable quantity, but seldom 

 seen growing. Berwick Bay, Sharper Head, Bummouth, Holy 

 Island. 



Desmarestia ligtjlata (Lightf.) Lamour. 



Ess., p. 25. — Fucus ligulatus, Light/., Fl. Scot., p. 946, t. 29. 

 Descr. Desmarestia ligulata, Harv., Phyc. Brit. 

 Fig. „ „ Harv., I.e. pi. 115. 



Exsicc. „ „ Wyatt, Alg. Danmon., no. 55 ; Cm., Ah'. 



Finist., no. 94. 



