THE BROWN SEAWEEDS OF THE SALT MARSH. 351 
boulders. Coasts of Scotland: Shetland Is. to Solway Firth; Ireland: 
Roundstone Bay. Baltic Sea. Connecticut. 
Ascophyllum nodosum у. Маскат, Cotton, in Proc. Roy. Irish Acad. xxxi. 
(1912) pp. 128, 129. 
Fucus nodosus v. Mackaii, С. А. Ag. Syst. p. 275 (1824). 
Fucodium nodosum у. В. Mackait, J. Ag. Spec. Alg. p. 206. 
Fucus Mackaii, Dawson Turner, Hist. Fue. pl. 52 : Harvey, Phyc. Brit. 
vol. 1. pl. 52; non €. А. Ag. Spec. Ale. p. 87. 
slscophyllum Mackaii, Holmes & Batters, in Ann. Dot. у. (1890-91) p. 85 ; 
Oltmanns, Beiträge zur Kenntuiss der Fucaceen, p. 43. 
Physocaulon Mackaü, Kütz. Рус. Gen. p. 352. 
Fucus SPIRALIS, L. = Fucus platyearpus, Thur. 
Thallus very variable in size and form, generally 2-5 dm. long and 
1-2 ems. broad ; attached by а dise. Branching dichotomous or sympodial, 
the lateral branches variable, single or forked. Margin smooth. — Air-vesicles 
absent or represented by irregular blister-like swellings. © Cryptostomata 
numerous and prominent, scattered over the entire wing of thallus. 
Fruit-bodies egg-shaped, blunt, swollen, and often margined, generally 
simple. Hermaphrodite. 
Var. NANA, Kjellm. 
Habit dwarf. Frond 1-10 cms., tufted from the base. Cryptostomata 
prominent. Receptacles in some localities not produced. 
Hab. Оп rocks in very exposed places, or on steep mud- and sand-banks 
in salt marshes. Blackwater Marshes, Essex ; Whitby, Berwick ; Dorset ; 
Wales; Ireland: Roundstone Bay, Clew Вау; Canary Islands; coasts of 
Scandinavia ; French coasts. 
Fucus spiralis, L., у. nana, Kjellm. Handb. p. 11; Borgesen, in Journ. 
Linn. Soc., Bot. xxxix. (1909) р. 109, fig. 3. хз. Holmes, Alg. Brit. 
har. Exe. Fase. xi. (1901) : Whitby. Cotton, Clare Island Survey, 
1912, p. 124. 
Fucus platycarpus f. limitaneus, Thur. et Born. Études Phycologiques, 
p. 41 (1878); Sauvageau, Sur les Algues du Golfe de Gascogue, p. 85 
(Journ. de Bot. vol. xi. р. 268). Also Sauvageau, 1908, р. 87. 
Fucus vesiculosus v. limitaneus, C. Montagne, Histoire Naturelle des Iles 
Canaries—Plantes cellulaires, Paris, 1856, р. 139; De Toni, Syll. Alg. 
vol. iii. pp. 206-7. 
Fucus vEsICULOsUS, L. 
Thallus very variable in size and form, 1 dm. to more than 1 m. long 
and 4—40 mm. broad, diehotomous or pseudosympodial; margins smooth ; 
attached by a dise. — Air-vesieles in pairs on either side of the midrib, 
