W. WEST AND G. S. WKST : ALGA-FI,ORA OF YORKSHIRE. II9 



571. Dactylococcus bicaudatus A. Br. 



[Syn. Charcicium longipes Reinsch]. 

 N.W. — Cautley Spout. 



Var. exilis West & G. S. West. 

 S.W\ — Horton Park, Bradford, forming a mucous, green 

 stratum on wet stones. 



Mid W. — Langclifl'e, near Settle. Ingleton. 

 N.W.— CowgiU Wold Moss, Widdale Fell. 

 Var. subramosum ^^'est &: G. S. West. 

 N.W. — Mossdale Moor, Widdale Fell, forming a green stratum 

 on dripping rocks. 



This variety is smaller than the type, and the cells are less 

 attenuated, concatenate and ramose. Diam. cell 3'8— 6'5 //. 



Genus SCENEDESMUS Meyen, 1S29. 



572. Scenedesmus antennatus Breh. 

 Mid W.— Langcliffe, near Settle. 



N.W\ — Near Jervaulx Abbey. 



N.E. — Pilmoor, near Thirsk. Scarborough Mere. 



S.E. — Skipwith Common. 



573. Scenedesmus obliquus (Turp.) Kiitz. 



[Syn. S. aadus Meyen]. 



S.W.— Ravvcliffe (H. F. Parsons). Heaton. 



Mid W.— Markington ! (Rev. J. S. Tute). Bramhope (J. 

 Abbott). Adel. Arthington. Hawksworth. Wigton Moor. 

 Boston Spa. Malham Tarn. Arncliffe. Moughton Fell. 



N.W. — Mickle and Cronkley Fells. Near Jervaulx Abbey. 



N.E.— Near Rievaulx Abbey. Strensall ! (W. B. Turner). 

 Scarborough Mere. Scalby Beck. 



Var. dimorphus (Turp.) Rabenh. 



S.E.- — Skipwith Common. 



574. Scenedesmus bijugatus (Turp.) Kiitz. [Syn. .S*. 

 obtusus Meyen; S. quadricmida (Turp.) Breb. var. 

 ecoruis (Ehrenb.) Ralfs]. 



S.W.— Rawcliffe (H. F. Parsons). Bradford. Cullingworth. 



