128 BRITISH DESMIDIACE^l. 



ENGLAND. Cocket Moss, Giggleswick Common, bog 

 two miles S. of Clapham, W. Yorks ! Suttoii Park, 

 Warwick (IF///*). Esher Common and near Chapel 

 Wood, Surrey ! 



WALES. Cap el Curig, Moel Siabod, and Glyder 

 Facli, Carnarvonshire ! 



SCOTLAND. Sutherland ! , Ross ! , Inverness ! , Aber- 

 deen, Kincardine, Forfar, Perth ! , Argyll, Arraii (Boi/ $ 

 Bissetty. Harris and Lewis, Outer Hebrides! 



IRELAND. Galway! Kerry! Donegal! Dublin and 

 Wicklow (Archer). 



Geor/r. Distribution. France. Germany. Austria. 

 Norway. Sweden. Denmark. Russia. Poland. Faeroes. 

 India. Java. New Zealand. United States. 



Some algologists have confused this species with Cl. inter- 

 nn-iliuni Ralfs, hut those ohservers cannot have seen both 

 species. Cl. Ulna is much less curved than Cl. intermedium 

 it is rather more elongate and is less attenuated towards the 

 extremities. The striolations of Cl. Ulna are exceedingly 

 delicate and from 14 to 20 are visible across the cell, whereas 

 those of Cl. intermedium are very strong and only 8 to 10 are 

 visible. 



13. Closterium juncidum Ralfs. 

 (PL XIV, figs. 10-14.) 



Closterium juncidum Ealfs, Brit. Desm. 1848, p. 172, t. 29, f . 6 ; Arch, in 

 Pritch. Infus. 1861, p. 749; Eabenh. Flor. Europ. Algar. Ill, 1868, 

 p. 127 ; Dolp. Desm. subalp. 1877, p. 115, t, 17, f. 11-14; Kirchn. Alg. 

 Schles. 1878, p. 137 ; Cooke, Brit. Desm. 1886, p. 30, t. 13, f. 7 ; Hansg. 

 Prodr. Algenfl. Bohm. 1888, p. 178; Boy & Biss. Scott. Desm. 189-1., 

 p. 245 ; Nordst. Index Desni. 1896, p. 151 ; West & G. S. West, Al-. S. 

 England, 1897, p. 482 ; Alg-a-fl. Yorks. 1900, p. 56 ; Alg. N. Ireland, 

 1902, p. 24. 



Cl. intermedium c. juncidum Klebs, Desm. Ostpreviss. 1879, p. 16, t. 2, 

 f. 5 I. 



Arthrodia juncida Kuutze, Revis. gen. plant. 1891, p. 883. 



Cells elongate and slender, 24-40 times longer than 

 their diameter, straight in the median portion and with 

 the margins parallel, towards the apices slightly in- 

 curved and attenuated ; apices obtusely rounded ; cell- 

 wall brown or reddish-brown, sometimes only pale 



