W. WEST AND G. S. WEST: ALGA-FLORA OF YORKSHIRE. 211 



995- Nitzschia Tryblionella Hantzsch. 



[Syn. Tryblionella gracilis W. Sm.]. 

 S.W.— Goole (J. Harrison). Roche Abbey (M. H. Stiles ; 

 J. N. Coonibe). Doncaster town water ; Firsby reservoirs ; 

 Rossington (M. H. Stiles). 

 N.E.— Saltburn. 



S.E. — Market Weighton. Stoneferry; Hornsea Peat Deposit 

 (G. Norman). 



996. Nitzschia angustata (W. Sm.) Grun. 



[Syn. Tryblionella angustata W. Sm.J. 

 S.W.— Roche Abbey (M. H. Stiles ; J. N. Coombe). 

 S.E. — Newsholme. Beverley!; Market Weighton Canal; 

 Anlaby (G. Norman). 



997. Nitzschia constricta (Kiitz.) Pritch. 



[Syn. N. diibia W. Sm.]. 

 S.W.— Goole (J. Harrison). 



Mid W. — Boston Spa. Hawksworth Springs. Bolton Woods. 



Ribblehead. 



S.E. — Beverley. Loftsome Bridge, near Wressle. Tickton. 



Routh. Near Meaux Abbey. Waghen. Market Weighton. 



Cottingham; near Stoneferry; Wawne; Haltenprice; Dairycoats; 



' Anlaby to Hessle Road ; Skirlaugh; Stepney Lane (G. Norman). 



Forma minor Rabenh. 



Mid W.— Baildon. 



S.E.— Market Weighton. 



998. Nitzschia plana W. Sm. 



S.E. — Brackish ditch, near River Hull (G. Norman). 



999. Nitzschia parvula W. Sm. 



Often found on damp ground and amongst damp moss. 



S.W. — Doncaster. Roche Abbey (J. N. Coombe). Ogden 

 Clough. 



]ViiD W. — Boston Spa. Bolton Woods. Holden Gill, near 

 Keighley. 



N.W.— Great Shunnor Fell. 



N.E.— Strepsall. Marske, Rievaiilx Abbey, 



