Marine Algce of the Ditnhar Coast. 287 



Pohjsiplionla Jihrillosa, Chondrus cHspus, Gigaiiina mamiUosa, 

 CladopJwra i-upestris, Fucus serratus, Fucus vesiculosus, Fuctis 

 2')lat year pus. 



82a. Porphyra laciniata (Lightf.), Ag., var. vulgaris (Ag.), Le Jolis. 



Common on rocks, and epiphytic on Algie, in pools between tide 

 marks. AnnuaL May to October. Fruit in August and September. 

 Host plants : Chondrus crispus, Dumoiitia Jfliformis, Fucus ser- 

 ratus, Fucus vesiculosus. 



82b. Porphyra linearis, Grev. 



On rocks at about the high-water mark of neap tides. "Winter 

 and spring. 



83. Poi-phjrra leucosticta, Thur. 



Epiphytic on Algae from about half-tide level to low-water mark. 

 Usually left uncovered by the tide, and exposed to the light for 

 several hours daily. Annual. May to October. Fruit best in 

 September. Host plants : Fucus serratus, Fucus vesiculosus, Fuctis 

 plati/carpus, Callithamnion arhuscula, Himantlialia lorea. 



BANGIA, Lyngb. 



84. Bangia fusco-purpiirea (Dillw.), Lyugb. 



On smooth rocks and stones at and above half-tide level. 

 Usually left uncovered by the tide, and exposed to the light for 

 some hours daily. Sometimes abundant at the "Vault," Brox- 

 mouth, but rather uncertain in its appearance. Annual. March to 

 September. Fruit in May and June. 



Family.— SQUA]VIAEIACE.E. 

 PETROCELIS, J. Ag. 



85. Petrocelis cruenta, J. Ag. 



On rocks usually at about low-water mark. Perennial. Fruit in 

 winter. 



CRUORIA, Fries. 



86. Cruoria pellita, Fries. 



On rocks at about half-tide level; also epiphytic on stems of 

 Laminaria hyperhorea. All the year. Fruit in winter. Rather 

 rare. 



Family.— HILDENBRANDTIACE.E. 



HILDENBRANDTIA, Nardo. 



87. Hildenbrandtia rosea, Kiitz. {IlihlcabramUia rubra, Meneg.) 



On pebbles and smooth stones in shallow pools, generally at about 

 half-tide level. Always submerged. All the year. Fruit in autumn 

 and winter. 



