356 The Alga-Flora of Mid' Lothian. [Sess. 



duriog this last summer, and a careful investigation of these 

 would no doubt produce many more species than could be 

 obtained during my few visits. 



My reasons for publishing this incomplete list of freshwater 

 Algse at present are the three following. The only record of 

 these plants is that given by Dr K. K. Greville in his ' Flora 

 Edinensis' in 1824, and the total number of freshwater Algse 

 mentioned by him is only 48, including several doubtful 

 species. Again, I believe that in the near future more atten- 

 tion will be paid to these primitive plants, as we soon may be 

 in possession of a systematic work describing all the species 

 found, so far, in Great Britain and Ireland. The lack of such 

 a book has no doubt contributed to the neglect from which 

 this branch of Botany has hitherto suffered. The list now 

 given may then prove of some assistance to those of our mem- 

 bers who should take up this particular study. Lastly, owing 

 to my leaving this country I shall be unable, for the present 

 at least, to continue my investigations in Mid-Lothian. 



I should like to mention here that two works published in 

 the United States of America, and which are therefore not so 

 well known to our members, have proved to be of consider- 

 able help in my work. These are F. S. CoUins's ' The Green 

 Algae of North America,' with 1 8 plates — Tuft's College, Mass., 

 1909 ; and T. E. Hazen's 'The Ulothricacese and Chaetophor- 

 acese of the United States,' with 23 plates — Memoirs of the 

 Torrey Botanical Club, New York, 1902. 



I owe a debt of gratitude to Professor G. S. West, of 

 Birmingham University, not only for his admirable ' Treatise 

 on the British Freshwater Algae,' but mainly for his kind 

 assistance in correcting and identifying most of the species 

 contained in my list. Owing to his help I can claim that 

 this modest contribution to our Alga-flora can be considered 

 free from doubtful members of the freshwater Algae. 



Class I.— EHODOPHYCE^ (or FLOKIDE^). 

 Order— WEMAIiIONACE^. 

 Family — Helminthocladiese. 



1. Batrachospermum moniliforme Eoth. 



Fairly common in running water, Pentland Hills. 



2. B. vagum (Rotli) Ag. 



Pond in Royal Botanic Garden. April-July. 



