W. WEST AND G. S. WEST: ALGA-FLOUA OF YORKSHIRE. 123 



Mid W. — Arthington. Cowside Beck, Arncliffe. 

 N.W.— Cautiey Spout. 



584. Rhaphidium biplex Reinsch. 

 N.E. — Pilmoor, near Thirsk. 



S.E. — Skipwith Common. 



Gexus SELENASTRUM Reinsch, 1867. 



585. Selenastrum gracile Reinsch, 1867. 



Mid W. — Langcliffe, near Settle. Small forms, diam. cell 

 2—2-3 M- 



586. Selenastrum acuminatum Lagerh., 1882. 

 S.E. — Skipwith Common. 



GENU.S CHODATELL.V Lemmefmanii, 1S98. 



587. Chodatella radians (West & G. S. West), Lemmer- 

 mann, r898. [Syn. Oocystis ciliata Lagerh. var. 

 radians West & G. S. West, 1896]. 



N.E. — Pilmoor, near Thirsk. 



S.E. — Skipwith Common. 



This plant was first described as a variety of Oocystis ciliata 

 in Journ. Roy. Micro. Soc, 1896, p. 161, t. iii., f. 15. Shortly 

 afterwards Chodat (Sur le genre Lagerheimia, Nuova Notarisia, 

 1895) referred Oocystis ciliata to his genus Lagerheimia, and 

 finally both Oocystis ciliata and the var. radians have been re- 

 ferred by Lemmermann (Hedwigia, Bd. xxxvii., 1898) as 

 separate species of the genus Chodatella. 



Genus TETRAEDRON Kiilz., 1845. 



588. Tetraedron regulare Kiitz., 1845. 



[Syn. Polyedrium tetra'edricuin Nag., 1849]. 



MiD W. — Wigton Moor. Markington ! (Rev. J. S. Tute). 

 Cocket Moss, near Giggleswick. 



N.W.— Cowgill Wold Moss, Widdale Fell. Mickle Fell. 

 Dodd Fell. 



N.E. — Pilmoor, near Thirsk. Malton. 



S.E. — Riccall Common, 



