234 BRITISH DESM1DJACE.E. 



202. Cosmarium Boeckii Wille. 

 (PI. LXXXVI, figs. 26-32.) 



Cosmarium Boeckii Wille, Norges Ferskv. Alg. 1880, p. 28, t. 1, f. 10; 



Boldt, Siber. Chlorophy. 1885, p. 106; Cooke, Brit. Desm. 1887, p. Ill, 



t. 42, f. 4 [figure bad] ; Nordst, Bornh. Desm. 1888, p. 196 ; De Toni, 



Syll. Alg. 1889, p. 1024 ; West, Alg. N. Wales, 1890, p. 290 ; Heimerl. 



Desm. alpiii. 1891, p. 597 ; West, Alg. W. Ireland, 1892, p. 157 ; Alg. 



En o-l. Lake Distr. 1892, p. 728 ; Schmidle, Alg. Geb. Oberrheins, 1894, 



p. 551, t. 28, f. 10; Eoy & Biss. Scott. Desm. 1894, p. 42; West & G-. S. 



West, Some N. Amer. Desm. 1896, p. 251, t. 15, f. 7 [forma] ; Alg. S. 



England, 1897, p. 489 ; Alga.-fl. Yorks. 1900, p. 77 ; Borg. Freshw. Alg. 



Faroes, 1901, p. 226 ; West & GK S. West, Alg. N. Ireland, 1902, p. 38 ; 



Freshw. Alg. Orkneys and Slietlands, 1905, p. 20. 

 Ursinella Boeckii Kuntze, Eevis. gen. plant. 1891, p. 924. 

 Cosmarium anisochondrum Nordst. forma Borge, Beitrage Alg. Schweden, 



1906, p. 32, t, 2, f. 17. 



Cells somewhat small, very slightly longer than 

 broad, very deeply constricted, sinus narrowly linear; 

 semicells trapeziform-semicircular, lateral margins 

 convex, incised-crenate, crenations 3, upper and lower 

 emarginate, middle crenation entire and subacute, 

 apex truncate, and 4-5 (generally 5) -undulate-nodu- 

 lose, with two series (rarely only one) of granules 

 within the maro-in, with more granules in the outer 



o o 



series than in the inner ; in the centre with a rather 

 slight but broad tumour, usually furnished with 4 

 granules disposed in a cruciate manner, lower granule 

 situated immediately above the isthmus and often 

 stronger than the others. Side view of semicell 

 obovate-circular, margin with 9-12 granules. Vertical 

 view elliptic, poles 5-granulate, with a slight and 

 broad 3-granulate tumour on each side. Chloroplasts 

 axile, with one pyrenoid. 



Zygospore unknown. 



Length 29-38 p; breadth 27-35'Oju; breadth of 

 isthmus 8-13 /x; thickness 17 19/x. 



ENGLAND.- -Cumberland ! Westmoreland ! (Bissett}. 

 W. and jST. Yorks ! Cheshire (Roy). Leicestershire 

 if). Surrey! Kent! Hants! Cornwall! 



WALES.- -Capel Curig, Llyn Ogwen, Yr Orsedd, and 

 Moelfre, Carnarvonshire ! 



SCOTLAND.- -Sutherland ! Ross, Inverness (in Skye), 



