W. WEST AND G. S. WEST : ALGA-FLORA OF YORKSHIRE. 35 



N.W. — Cronkley and Mickle Fells, frequent. 



N.E.— Strensall (W. B. Turner). Pilmoor, near Thirsk. 



125. Zygnema ericetorum (Kiitz.) Hansg. [Syn.Zygo- 

 gonium ericetorum Kiitz. ; Z. ericetorum var. a ferrestris 

 Cooke and var. /8 aquaticum Cooke ; Z. Agardhii 

 Rabenh. ; Z. didymum Rabenh.]. 



On damp heaths, etc., more or less abundant, forming dark- 

 green patches, which often inchne to violet. Also frequent in 

 peaty ditches on upland moors, the filaments often attaining a 

 length of several feet. The aquatic form {ioxxca. fluitans (Kiitz.) 

 Rabenh.) and the terrestrial form (forma terrestre Kirchn.) are 

 practically indistinguishable, the former growing equally well on 

 damp peat, although assuming a darker colour. 



S.W. — Goole. Thornton. Harden. Keighley Moor. 



Mid W. — Bramhope (J. Abbott). Baildon. Rombald's Moor. 

 Simon Seat. Malham (C. B. Crawshaw and C. P. Hobkirk). 

 Giggleswick Common. Bowland Knotts. Ingleborough. Peny- 

 ghent. Old Cote Moor. Cray Moss. 



N.W. — Mickle, Cronkley, and Great Shunnor Fells. Swale- 

 dale, up to 2,200 feet. Mossdale Moor, Widdale Fell. Dodd 

 Fell and Lund's Fell, up to 2,000 feet. 



N.E.— Strensall ! (W. B. Turner). Pilmoor, near Thirsk. On 

 damp ground, Whitenab, Scarborough. 



126. Zygnema leiospermum DeBary. 



S.E. — Very fine, from Loftsome Bridge, near Wressle. 



127. Zygnema insigne (Hass.) Kiitz. 

 Mid W. — Malham (vii. 1891). 



Genus SPIROGYRA Link, 1820. 



128. Spirogyra tenuissima (Hass.) Kiitz. 

 S.W.— Frizinghall. Heaton. 



Mid W. — Hawksworth. Baildon. Buckden. 



N.W.— River Ure. 



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



129. Spirogyra inflata (Vauch.) Rabenh. 



[Syn. S. tenuissima forma inflata (Vauch.) Cooke]. 



