194 BRITISH DESMIPIACEJE. 



and plankton of Lough Beg, Londonderry ! Plankton 

 of Lough Neagh and of Upper River Bann ! Lough 

 Derryadd, Armagh ! 



Geogr. Distribution. Germany. Galicia in Austria. 



This variety differs so little from tlie type that it is scarcely 

 possible to distinguish between them. It also closely resembles 

 in outline C. Phaseolus Breb. var. elevatum Nordst., but the 

 vertical view does not possess the median protuberances. 



44. Cosmarium galeritum Nordst. 

 (PL LXIII, figs. 24, 25.) 



Cosmarium galeritum Nordst. Desm. Brasil. 1870, p. 209, t. 3, f. 26 ; 



Wolle, Desm. U. S. 1884, p. 70, t. 16, f. 46, 48 ; Cooke, Brit. Desm. 



1886, p. 87, t. 42, f. 14 [figures bad] ; De Toiii, Syll. Alg. 1889, p. 976 ; 



West, Alg. N. Yorks. 1889, p. 292 ; Alg. N. Wales, 1890, p. 288 ; Add. 



Alg. W. Yorks. II, 1891, p. 245 ; Alg. W. Ireland, 1892, p. 145 ; Koy 



& Biss. Scott. Desm. 1894, p. 101 ; Nordst. Index Desm. 1896, p. 128 ; 



West & G-. S. West, Alga-fl. Yorks. 1900, p. 74 ; Alg. N. Ireland, 1902, 



p. 32. 

 Ursinella galerita Kuntze, Revis. gen. plant. 1891, p. 924. 



Cells of moderate size, about ly times longer than 

 broad, deeply constricted, sinus narrowly linear with a 

 dilated extremity, slightly widening outwards ; semi- 

 cells pyramidate-trapeziform or truncate-pyramidate, 

 basal angles well rounded, sides almost straight or 

 slightly convex, upper angles rounded, apex narrowly 

 truncate and generally slightly convex. Side view of 

 semicell subcircular. Vertical view elliptic, ratio of 

 axes about 1 : 1'9. Cell-wall punctate. Chloroplasts 

 axile, each with two pyrenoids. 



Zygospore unknown. 



Length 51-56*5 ^ ; breadth 42-46 ju; breadth of 

 isthmus 1 5*5-17 ^ ; thickness 23-24 jn. 



ENGLAND. - Helvellyn, Westmoreland ! Mai ham 

 Tarn, Penyghent, Cocket Moss near Giggleswick, and 

 Roundhay Park near Leeds, W. Yorks ! Pilmoor near 

 Tbirsk, Mickle Fell, and Great Shunnor Fell, N. 

 Yorks! Riccall Common, E. Yorks! Enbridge Lake, 

 Hants (Roy). Cornwall (Marquand). 



WALKS.- -Llyn Coron, Anglesey ! 



