1887-88.] Marine Algoi of E lie. 171 



149. Porphyra Icucostida, Thiiret. 



Epiphytic on Algae from half-tide level to low-water 

 mark. Annual, May to October. Fruit best in 

 September. 



150. Porphyra vulgaris, Ag. 



On rocks and Algte in pools between tide marks. 

 Annual, May to October. Fruit in August and 

 September. 



151. Prasiola marina, Crouan. 



On rocks and boulders at about the high-water mark 

 of neap tides. All the year. In best condition in 

 winter and spring, and generally poor in sum- 

 mer and autumn. Fruit in February and March. 



152. Protococcus (species'?), Thuret. 



At 2 and 3, on rocks and stones in brackish pools 

 above high-water mark; also epiphytic on Entcro- 

 morpha compressa. 



153. Ptilota elegans, Bonnem. 



At 3, 7, 12, &c., on shaded rocks and boulders, and in 

 dark crevices, from a little below half-tide level to 

 low-water mark. Perennial. Fruit in spring and 

 summer. 



154. Ptilota plumosa, Ag. 



Cast ashore from deep water. Epiphytic on 

 Laminaria Cloustoni. Perennial. Fruit, June, 

 July, August. 



155. Punctaria plantaginea, Grev. 



At 5, 6, and 12, in pools from about half-tide level to 

 near high-water mark. Annual, March to July. 



156. Punctaria tenuissima, Grev. 



At 2, in deep pools, epiphytic on Laminaria fiexicaulis 

 and Laminaria saccharina. Annual. Fruit in 

 August and September. 



157. Balfsia verrucosa, Harv. 



At 3, 12, &c., in shallow pools between high-water 

 mark and half-tide level, incrusting rocks and 

 stones ; also on exposed rocks in damp places. 

 Perennial. Fruit in July and August. 



158. Phodomela lycopodioidcs, Ag. 



Cast ashore, epiphytic on Laminaria Cloustoni. Peren- 

 nial. Fruit from March to June. 



