Clare Island Survey. 



15 

 MARINE ALGAE. 



By A. D. COTTON. 

 Plates I.-XI. 



Read Juke 24 and November 11. Published November 27, 1912. 

 CONTENTS. 



Preface, 



1 





iii. The Salt-marsh Formation, . 



:s 



Introduction, .... 



2 





iv. The Vegetation of River- 





1. Definition of the Area, 



2 





mouths, .... 



S3 



2. Previous work in the Area, 



2 





v. The Vegetation of Brackish 





3. Field-work and Assistance, 



4 





Bays, .... 



8S 



I. The External Conditions of the 





III. 





90 





6 





1. The Systematic List, 



90 



1. Climatic Conditions, 



6 





2. Notes on the List, 



102 



2. Physical Nature of the Coast. 







3. Economic Species, 



151 



and Conditions of Exposure, . 



9 





4. The Flora of The Bills, . 



155 



I. The Algal Vegetation, . 



12 



IV 



The Character and Composition 





1. Historical Resume, . 



12 





of the Flora, 



156 



2. Areas and Units of Vegetation, . 



11 





1 . Notes on Novelties and Additions, 



156 



3. The Vegetation, 



17 





2. The Character of the Flora, 



160 



i. The Rocky-shore Formation, 



17 





3. Comparison with other Areas, . 



166 



(A) Exposed Coasts, 



19 





4. Origin of the Flora, . 



16S 



(B) Sheltered Coasts, 



50 



V 



Bibliography, .... 



171 



ii. The Sand and Sandy-mud 











Formation, 



61* 









PEEFACE. 



The natural history Survey of Clare Island and the adjoining mainland 

 provided an opportunity of investigating one of the most interesting 

 algological regions in the British Isles. Since the first decade of the last 

 century, when Miss Hutchins collected in Bantry Bay, and more especially 

 since the days when Harvey published his famous " Phycologia Pritannica," 

 the west of Ireland has always possessed a great attraction for the marine 

 botanist. But although various collections and many gatherings of new and 

 rare species have been dealt with, no systematic investigation of that area 

 has been undertaken, nor has any list or general account of the algal flora been 

 published. The selection of Clare Island as a centre for a detailed survey was 

 therefore particularly satisfactory from an algological standpoint. Results 

 for the systematist and student of plant-distribution were certain, and the 



R.I. A. PROC, VOL. XXXI, A 15 



