W. WEST AND G. S. WEST: ALGA-FLORA OF YORKSHIRE. II3 



A variety of this species was observed on wet limestone rocks 

 at Boston Spa. It was smaller than the type with globose 

 oogonia. Thickness of filaments, 25-30 /*. 



Family HYDROGASTRACE^. 

 Genus BOTRVDIUM Wallr., 1815. 



538. Botrydium granulatum (L.), Grev. 



S.W. — Calverley (vi. 1893), in great profusion on mud turned 

 out from the canal. Shipley (ix. 1895), on mud turned out from 

 the canal. Near Gilstead, close to the river Aire. 



Mid W. — Adel Dam, on drying-up mud (J. Abbott) ; this was 

 many years ago, and it has not been seen there since. Brearton, 

 near Knaresborough. 



Order PROTOCOCCOIDE.^. 



Family VOL VOC/NE.E. 



Genus VOLVOX Ehrenb., 1S32. 



539. Volvox globator (L.), Ehrenb. 



S.W. — Still waters, somewhat rare, but fairly general. Hatfield 

 Chase (J. M. Kirk). Askern (Rev. F. H. Allen). Rawcliffe ! (T. 

 Hick). Frizinghali. Hunslet Old Race-course (J. Abbott). 



Mid W. — Markington ! (Rev. J- S. Tute). Bramham Park 

 (B. Saynor). Roundhay (R. Duncan). Bramhope ; pool by the 

 Ure at Ripon (J. Abbott). Harrogate (J. M. Kirk). 



N.E.- Strensall (W. B. Turner). 



S.E.— Kirkham Abbey (J. M. Kirk). 



540. Volvox aureus Ehrenb. 



S.W. — Goole ; Midgeley Moor ; Salterhebble, near Halifax ; 

 Thornhill Lees (T. Hick). 



Mid W. — Askham Bog ; near Wetherby (T. Hick). 

 N.E.— Strensall (T. Hick). Pilmoor, near Thirsk. 



Genus EUDORINA Ehrenb., 1832. 



541. Eudorina elegans Ehrenb. 

 S.W, — Frizinghali. Goole. 



N.E. — Pilmoor, near Thirsk. Terrington. 

 S.E. — Skipwith Common. 



