CLOSTEK1UM. 



3. Closterium Archerianum Cleve. 

 (PL XI, figs. 8-10.) 



Closterinm Archerianum Cleve, in Lund. Desm. Siiec. 1871, p. 77, t. 5, 



f. 13 ; Jacobs. Desm. Danem, 1875, p. 175, t. 7, f. 4; Cooke, Brit. Desm. 



1886, p. 27, t. 13, f . 5 ; West, Alg. N. Wales, 1890, p. 285 ; Alg. W. 



Ireland, IS'.C.', p. 123; Roy & Biss. Scott. Desm. 1894, p. 243; Nordst. 



Index Desm. 1896, p. 50; West & G. S. West, Alg. S. England, 



1S!>7, p. 481; Liitkem. Desm. Millstattersees, 1900, p. 3 (sep.) ; West 



cV G. S. West, Alg. N. Ireland, 1902, p. 24. 

 Closterium Archerianum a. typicum Klebs, Desm. Ostpreuss. 1879, 



p. 13, t. 1, f. 13 7i, t. 2, f. 1. 

 Arthrodia Archeriana Kuntze, Revis. gen. plant. 1891, p. 883. 



Cells of medium size, about 11 times longer than 

 the diameter, strongly curved, outer margin about 

 123-145 of arc, inner margin not tumid, gradually 

 and regularly attenuated to the apices, which are 

 narrow and obtusely rounded ; cell-wall pale yellow or 

 brown in colour, striate, stride rather variable, from 8 

 to 11 visible across the cell; each chloroplast with 

 5 or 6 pyrenoids ; terminal vacuoles indistinct, with 

 one moving granule. 



Zygospore subglobose and smooth. 



Distance between apices 196-230 /A ; breadth 

 18'5-30/A; diam. zygosp. 36-46 ju. 



ENGLAND. Loughrigg and Bowness, Westmoreland ! 

 Delamere, Cheshire (Roy). New Forest, Hants ! 

 Grunwen Moor, Cornwall ! 



WALES. Capel Curig and Llyn Padarn, Carnarvon- 

 shire ! 



SCOTLAND. Ross, Aberdeen, Kincardine, Forfar, 

 Perth, Stirling, Argyll (Roy $> JHssctt). Rhiconich 

 and Loch Inver, Sutherland ! 



IRELAND. Mayo ! Galway ! Kerry ! Donegal ! 

 Dublin and Wicklow (Archer) . Antrim ! Armagh ! 



(li'ntji-. Distribution. France. Germany. Austria. 

 Norway. Sweden. Denmark. Lapland. Russia. 

 India. Java. Azores. 



We give a figure (PI. XI, fig 1 . 11) of a coarsely striated form 

 of this species which somewhat approaches Cl. porrectum var. 

 anyustatum. 



