\V. WEST AND G. S. WEST: ALGA-FLORA OF YORKSHIRE. 213 



T007. Nitzschia vivax W. Sm. 

 S.E. — Near Stoneferry (G. Norman). 



1008. Nitzschia dissipata (Kiitz.) Grun. 



[Syn. ? JV. mt?iutissima W. Sm.J. 



Mid W. — Roundhay (W. B. Turner). Baildon. Hawksworth 

 Springs. Malham Tarn. 



N.W.— Mickle Fell. 



N.E. — Whitby. Seamer. Rievaulx Abbey. Strensall (W. B. 

 Turner). 



S.E.— Near Hull (G. Norman). 

 Var. media Van Heurck. 



Mid W. — Hawksworth Springs. Penyghent. 



S.E. — Market Weighton. 



1009. Nitzschia Sigmoidea (Ehrenb.) VV. Sm. 



S.W. — Abundant in the Bradford, Halifax, and Keighley dis- 

 tricts. Cusworth and Hatfield districts; Firsby reservoir; 

 Rossington (M. H. Stiles). Askern ; Hatfield Chase (J. M. 

 Kirk). Roche Abbey Q. N. Coombe). Doncaster. Wibsey. 

 Allerton. 



Mid W. — Malham Cove (J. M. Kirk). Arthington. Bolton 

 Woods. Staveley Dam, near Knaresborough. Whernside. 



N.W.— Dodd Fell. Mickle and Cronkley Fells. 



N.E. — Seamer. Near Scarborough. Malton. Carlton Bank. 



S.E. — Beverley. Routh. Market Weighton. Skipwith Com- 

 mon. Cottingham; Risby Pond; AVawne; Haltenprice; Spring 

 Ditch ; Beverley (G. Norman). 



loio. Nitzschia vermicularis (Kiitz.) Grun. 

 S.W.— Hatfield district (M. H. Stiles). 



loii. Nitzschia Br^bissonii W. Sm. 

 Mid W.— Gordale. 

 S.E. — Near Stoneferry (G. Norman). 



1012. Nitzschia Sigma (Kiitz.) W. Sm. 

 S,W.— Goole (J. Harrison). 



Pot. s— N 



