392 76. Mackaia. 2. THALASSIOPHYE&. Pl. cell. aph. 
1. Mackaia abrotanifolia. Southern-wood mackay. 
Thallus threadlike, compressed, bipinnate; lobes alter- 
nately forked, threadlike, spreading, edge not cut; vesicles 
innate; apothecia terminal, many cleft. 
Fucus abrotanifolius, Lin. S. P. 1629; Turn. Hist. 252; Engl. Bot. 
2130. 
Sea-shore; perennial; winter. 
Thallus 12 to 18 inches long; rough at the base. 
2. Mackaiza discors. Discordant mackay. 
Thallus round, branched; branches. alternately pin- 
nate; lower branches winged, serrated; upper branches 
linear ; apothecia terminal, oblong. 
Fucus discors, Lin. Syst. Nat. 2,711; Turn. Hist. 252; Engl. Bot, 213k. 
Sea-shore; perennial; summer. 
Thalli many, crowded, rough.— According to Mrs. Grif 
fiths is the young state of the preceding species. 
3. Mackaia barbata. Bearded mackay. 
Thallus round, very much branched; branches alternate, 
threadlike; apothecia oblong, acute, terminal. 
Fucus barbatus, Woodw. Tr. Lin. Soc. 3,128; Lurn. Hist. 250; Engl. 
Bot. 2170. : 
Fucus feeniculaceus, Gmel. 86. 
Sea-shores; perennial; summer. 
6. granulata. Apothecia linear, tubercular. 
Fucus granulatus, Woodw. Tr. Lin, Soc. 3,131. 
4. Mackaia fibrosa. Fibrous mackay. 
Thallus compressed and woody at the base; branches 
9-rowed, long, variously divided; upper branches with 
bristlelike twigs, lower branches naked; vesicles roundish, 
innate; apothecia cylindrical. 
Fucus radicibus arborum fibrosis similis, Rati Syn. 49, 45. 
Fucus fibrosus, Huds. Fl. Angi. 515; Eng. Bot. 1969; Turn. Hist. 209. 
Fucus setaceus, Huds. Fl, Angl, 575. 
Fucus barbatus, Gmelin, 90. 
Sea-shores; perennial; Feb. and August. 
Thallus 1 to $ feet high. 
5. Mackaia mucronata. Stiff-pointed mackay. 
Thallus round, warty, very much branched; branches 
threadlike, spinous; young branches linear, flat, not cut, 
mid-ribbed; ép stiff pointed; apothecia cylindrical. 
