W. WEST AND G. S. \VESt : ALGA-FLORA OF YORKSHIRE. 1 55 

 Genus CCELOSPH^RIUM Nag., 1849, 



771. Coelosphaerium Kiitzingianum Nag. 



Mid W. — Ingleborough. 

 N.W. — Jervaulx Abbey. 



Genus GOMPHOSPH/ERIA Kiitz., 1836. 



772. Gomphosphaeria aponina Kiitz., 1836. 

 Mid W.— Cam Fell (viii. 1896). 



N.E. — Pilmoor, near Thirsk. 



Genus CLATHROCVSTIS Henfrey, 1856. 



773. Clathrocystis aeruginosa (Kiitz.) Henfrey. 

 Mid W. — Pond, Boston Spa (iv. 1897). 



S.E. — Hornsea Mere, very fine. 



774. Clathrocystis roseo-persicinus (Kiitz.) Cohn. 

 [Syn. Protococcus roseo-persicinus Kiitz. ; Polycystis 

 roseo-persicinus (Kiitz.) Gutw., 1895]. 



S.W.— Bradford (ix. 1896). 



N.E. — Pilmoor, near Thirsk. Malton. 



Genus POLYCYSTIS Kiitz., 1845. 



775. Polycystis marg-inata (Menegh.) Richter. 

 [Syn. Microcystis marginata (Menegh.) Kiitz.; Ana- 

 cystis marginata Menegh.]. 



Mid W.— Old Cote Moor (viii. 1896). 



776. Polycystis elabens (Breb.) Kutz. 

 Mid W. — Roundhay Park, Leeds. 



N.E. — Pilmoor, near Thirsk. Carlton Bank. 



777. Polycystis Flos-aquae Wittr., 1879. 

 Mid W. — Boston Spa. 



778. Polycystis viridis A. Br., 1867. 

 N.E. — Pilmoor, near Thirsk. 



This species has not previously been recorded for the British 

 Isles. 



Genus GLCEOCAPSA Kiitz., 1843; em. Niig., 1849. 



779. Gloeocapsa didyma Kiitz. 

 Mid W.— Helln Pot, near Selside. 



