Marine Algw of the Orkneij Islands. 307 



30. Cladopliora laetevirens (Dillw.), Kiitz. 



On rocks, and epiph)i;ic on Algae, in pools, usually at about 

 half-tide level. Always submerged. Annual. March to December. 

 Plants sometimes live through the winter. Fruit in summer. 

 Young plants, and new shoots on old plants of the last season, have 

 their ramelli secund ; all the ramelli being produced on the inner 

 side of the ramulus previously to those on the outer side. Occurs 

 at Carness in pools. 



31. Cladophora gracilis, Griff. 



Usually grows on Zostera and the larger Algse in deep water. 

 Annual. Summer. Identified in Mr PoUexfen's collection by ]Mr 

 Edward Batters. 



32. Cladophora glaucescens (Gritf.), Harv. 



On rocks and stones between tide marks. Always submerged 

 Annual. Summer. 



33. Cladophora albida (Huds.), Kiitz. 



On rocks, and epiphytic on Algae, near low-water mark. Annual. 

 Summer. Common. 



33a. Cladophora albida, var. rcfrada (Harv.), Thur. 



In pools near low-water mark. Always submerged. Annual. 

 Summer. Common. 



34. Cladophora fracta {Fl. Dan.), Kiitz. 



Loch of Stenness ; also Holland Head, Inganess Bay, and 

 Scapa at high -water mark. Annual. Summer and autumn. 1887 

 (G. W. T.). Corroborated by E. M. Holmes. 



Family.— CODIACE^. 



CODIUM, Stackh. 



35. Codium tomentosuin (Huds.), Stackh. 



In pools, generally near low-w^ater mark. Occasionally epiphytic 

 on Poll/ides rotundus. Perennial. Summer. Clet, Westray ; 

 Linga Island (M'Bain,) fine ; Pharay Island ; Kirkwall Bay, opposite 

 Iceland Skerry ; Carness Bay, opposite Hellyar Holm ; South 

 Pionaldshay. 



FA3IILY.— BRYOPSIDE^. 

 BRYOPSIS, Lamour. 



36. Bryopsis plvimosa (Huds.), Ag. 



In pools at many places from about half-tide level to low-water 

 mark. Annual. May to October. 



