6 BRITISH DESMJDIAOEJ1. 



Yar. Tyrolicum Nordst. (PL LXV, figs. 11, 12.) 



C. cymatopleurum Nordst. var. Tyrolicum Nordst. Desm. Ital. 1876, p. 30,, 

 t. 12, f . 5 ; De Toni, Syll. Alg. 1889, p. 970 ; West, Alg. Engl. Lake 

 Distr., 1892, p. 724 ; Eoy & Biss. Scott. Desm. 1894, p. 44; West & 

 G. S. West, Alga-fl. Yorks. 1900, p. 80 ; Alg. N. Ireland, 1902, p. 37. 



C. subochthodes Schmidle, Weit. Beitr. Algenfl. Rheineb. u. Schwarzwald. 

 1895, p. 75, cum. fig. 26 a-c. 



Slightly larger than the type ; semicells subelliptic, 

 the whole margin slisrhtly undulate, basal angles less 



o o J o 



rounded ; apex not truncate ; cell- wall more distinctly 

 punctate. 



Length 80-108 ,u ; breadth 68-77 p. ; breadth of 

 isthmus 22-36 /u ; thickness 4750 ^u. 



ENGLAND.- -Hawkshead, Lancashire ! Shipley Grlen, 

 on wet rocks near Arncliff e, and Penyghent, W. Yorks ! 

 Lund's Fell, N. Yorks! Tremethick Moor, Cornwall! 



SCOTLAND. Near Aboyne and Corrie of Loch 



,/ 



Kandor, Aberdeen ; Canlochan (associated with var. 

 Archerii), Forfar ! (Roy fy Bissett). Rhiconich, Suther- 

 land ! 



IRELAND. Bog near Lough Neagh, Londonderry ! 

 Lough Shannacloontippen, Gal way ! Kenmare, Kerry ! 



Geogr. Distribution. --Germany. Italy. 



This variety is more frequently found than typical C. 

 cymatopleurum, and sometimes occurs in pure masses, forming 

 a pale green, gelatinous stratum on dripping rocks in the 

 more sheltered parts of rocky glens. C. microspliindum is 

 sometimes found amongst it. 



It differs from typical C. cymatopleurnm in its more inflated 

 semicells^ without a produced apex, and in the more uniform 

 undulation of the lateral margins. The cell- wall is also more 

 strongly punctate. When occurring in gelatinous masses an 

 exuviation of the outer layers of the cell-wall into the sur- 



V 



rounding mucus can be sometimes observed. 



Var. Archerii (Roy & Biss.) West & G. S. W r est. 



(PL LXY, fig. 10.) 



Cosmarium Archerii Eoy & Biss. Scott. Desm. 1894, p. 42, t. 1, f. 5. 

 C. cymatoplewum Nordst. var. Archerii (Roy & Biss.) West & G. S. West, 

 Notes Alg. II, 1900, p. 291, t. 412, f. 5 ; Alga-fl. Yorks. 1900, p. 80. 



