Marine Algce of the Orkney Islands. 325 



Family.— CRYPTONEMIACEJE. 



SARCOPHYIiLIS, Kiitz. 



155. Sarcophyllis edulis (Stackh.), J- Ag. {Indcm edulis (Stackh.), 



Bory.) 

 Common on rocks on exposed shores near low-water mark in the 

 shade. Perennial. Fruit in autumn and winter. 



HALYMENIA, Ag. 



156. Halymenia ligulata (Wood.), Ag. 



On rocks and stones near low-water mark ; also in deep water. 

 Annual. Summer. Dredged in Kirkwall Bay by Mr Pollexfen. 



FASTIGIARIA, Stackh. 



157. Fastigiaria fuxcellata (Linn.), Stackh. {Furcellaria fastigiata 



(Huds. ), Lamour.) 



On rocks, chiefly in sandy pools, near low-water mark. Always 

 submerged. Perennial. Fruit in winter. 



DUMONTIA, Lamour. 



158. Dumontia filiformis {Fl. Dan.), Grev. 



Common in rock pools at about half-tide level. All the year. 

 In best condition from March to October ; plants being stunted and 

 comparatively rare during winter. Fruit in summer. The variety 

 ft crispata also occurs, chieHy where there are fresh-water streams. 



Family.— GIG ARTINACEyE. 



CHONDRUS, Stackh. 



159. Chondrus crispus (Linn.), Lyngb. 



Common on rocks between tide marks. Perennial. Fruit in winter 

 and spring. 



GIGARTINA, Stackh. 



160. Gig-artina mamillosa (Good, and Wood.), J. Ag. 



Common on exposed rocks and in pools from half-tide level to 

 low-water mark. Perennial. Fruit in winter. 



GYMNOGONGRUS, Martins. 



161. Gymnogongrus Griffithsise (Turn.), Martins. 



On submarine rocks near low-water mark. Perennial. Fruit in 

 autumn and winter. Odin's Bay, Stronsay. 



162. Gjonnogong^us Norvegicus (Gunn), Lamour. J {Chondrus Norvegi- 



cics, Lamour.) 



Usually on rocks near low-water mark. Annual. September to 

 ^larch. 



