COSMARIUM. 41 



Cells rather under medium size, about 2i times 

 longer than broad, perfectly cylindrical with hemi- 

 spherical ends, median constriction very slight, sinus 

 a slight excavation; semicells oblong, with a rectangular 

 base, apex strongly convex. Cell-wall furnished with 

 emarginate verrucae (about 19 visible round the margin 

 of a semicell), disposed in regular vertical and hori- 

 zontal series, about 8 or 9 horizontal series and about 

 9 vertical series seen in front view. Vertical view 

 circular, with about 22 small nodulations round the 

 margin. Chloroplasts parietal, in three bands enclosing 

 two pyrenoids in each semicell. 



Zygospore unknown. 



Length 82-88 ju; breadth 33-37 /u; breadth of 

 isthmus 24-2 7 ,u. 



WALES.- -Capel Curig, Carnarvonshire (Roy tjj* 

 Bissett). 



IRELAND. Derryclare Lough, Gralway ! 



SCOTLAND. --Moidart, Inverness ! Powlair and 

 Slewdrum, Aberdeen ; Xear Bridge of Bogandreep 

 and Blackball in Strachan, Kincardine ; Grlen Garry 

 (Roy $- Bissett), Ben Lawers, and Loch Katrine, Perth! 



Geogr. Distribution.- -Sweden. Bohemia in Austria. 

 United States. 



Forma minor West. (PI. CII, figs. 20, 21.) 



C. elegantissimum Ltmcl. forma minor West, Alg. W. Ireland, 1892, p. 10-1, 

 t. 24, f. 10; Alg. Engl. Lake District, 1892, p. 730; W. & G-. S. West, 

 Alg. S. England, 1897, p. 492 [recorded as type] ; Borge, Trop. u. siib- 

 trop. Siissw.-Chlor. 1899, p. 19"; W. & Gr. S. West, Alga-n. Turks. 1900, 

 p. 94 [recorded as type]. 



Cells less than two-thirds the size of the typical form. 



Length 49-54 /A; breadth 22-23 p. ; breadth of 

 isthmus 17-19*5 //,. 



ENGLAND.- -Borrowdale, Cumberland ! Bo vrness and 

 Helvellyn, Westmoreland ! Xear Cockley Beck, Lanca- 

 shire ! Pilmoor, N. Yorks ! Skip with Common, E. 

 Yorks ! Thursley Common, Surrey ! Kew Forest, 

 Hants ! 



WALES. Yr Orsedcl, Carnarvonshire ! 



