38 YORKSHIRE NATURALISTS' U.NION. 



142. Spirogyra condensata (Vauch.) Kiitz. 



S.W. — Howley near Dewsbury (C. B. Crawshaw and C. P. 

 Hobkirk). Near Bradford. 

 Mid W.— Baildon. 



N.W.— Great Shunnor Fell. River Ure. Reeth. 

 N.E. — Scarborough Mere. 



143. Spirogyra velata Nordst. 



Mid W. — In stream, Shipley Glen. A rather smaller form than 

 the type. 



144. Spirogyra nitida (Dillw.) Link. 



S.W. — Howley, near Dewsbury (C. B. Crawshaw and C. P. 

 Hobkirk). Bradford. Wilsden. Marley, near Bingley. 



Mid W. — Bramhope and Adel (J. Abbott). Harrogate (T. 

 Hick). Malham. 



N.E. — Strensall (W. B. Turner). Scarborough Mere. 



145. Spirogyra crassa Kiitz. 



S.W. — Doncaster. Near Heckmondwike (C. B. Crawshaw and 

 C. P. Hobkirk). Manningham. 

 N.W.— Sedbergh. 

 N.E. — Scarborough Mere. 



Genus CHOASPIS S. F. Gray, 1821. 



146. Choaspis stictica (Eng. Bot.) O.K., 1891 [Syn. 



Conferva stictica Eng. Bot. ; Choaspis serpentaria S. F. 

 Gray, 182 1; Sirogonium sticiicum Kiitz., 1843]. 



S.W.— Keighley. 



Mid W. — Hawksworth. Baildon. Ingleton. 



The habitat given by Rabenhorst (Flor. Europ. Algar., iii., 

 p. 256), is 'in stagnis.' We have never obtained this plant except 

 where the water was running, generally at a spring and attached 

 to stones over which the water was flowing fairly fast. 



Gray's description of Choaspis (Arrang. Brit. PL, 182 1, vol. i, 

 p. 299) is a good one of the genus and twenty-two years previous 

 to Kiitzing's description of Sirogonium. His remark ' not slippery ' 

 is quite correct, and Choaspis is readily distinguished from Spiro- 

 gyra, Zygnema, etc., by touch alone. 



Trans. Y.N.U., 1896 (pub. Sept. 1900). Bot. Series, Vol. 5. 



