W. WEST AND G. S. WEST: ALGA-FLORA OF YORKSHIRE. 149 

 Genus OSCILLATORIA Vauch., 1803. 



737. Oscillatoria princeps Vauch., 1803. 

 Mid W. — Malham Tarn Bog; very fine, Aug. 1896. 

 N.E. — Pilmoor, near Thirsk ; vii. 1898. 



738. Oscillatoria limosa Ag., 181 2. 



[Syn. Oscillaria Frcelichii Kiitz., 1843]. 



S.W. -Bradford. Dewsbury. Frizinghall. Wibsey. Farnley. 



Mid W. — Wetherby (F, A. Lees). Baildon. Wigton Moor. 

 Malham. Moughton Fell. Penyghent. Pond at Pool. 

 Holden Gill, near Keighley. Eldwick. Boston Spa. Staveley 

 Dam, near Knaresborough. Ilkley. 



N.W. — Masham. Near Moorcock Inn. Great Shunnor Fell. 

 Mickle Fell. Dodd Fell. 



N.E. — Strensall. Scarborough Mere. Hayburn Wyke. 

 Stokesley. 



S.E. — Waghen. Beverley. Routh. Loftsome Bridge, near 

 Wressle. Newsholme, near Howden, 



739. Oscillatoria irrigua Kiitz., 1843. 



This species frequently forms dark purple velvety patches 

 over which the water runs quickly. 



S.W. — Keighley. Farnley. Near Halifax. 



Mid W. — Addingham. Arthington. Baildon. Oughtershaw 

 Moss, 



N.W. — River Ure. Duerley Beck near Hawes. Sedbergh. 



740. Oscillatoria tenuis Ag., 18 13. 



[Syn. Oscillaria tenuis var. viridis Kiitz., 1849J. 

 S.W. — Wakefield. Bradford. Frizinghall. Halifax. 

 Mid W. — Sherburn. Baildon. Leeds. Pond at Pool. 

 Staveley Dam, near Knaresborough. Ilkley. 

 N.W.— Sedbergh. Mickle Fell. 

 N.E. — Seamer. Malton. 



741. Oscillatoria amphibia Ag., 1827. 



[Syn. Oscillaria te?ierrima Kiitz., 1843]. 

 S.W. — Bradford. Frizinghall. Kildwick. Doncaster. 



Bot. 5-J 



