12 BRITISH DESMIDIACE.fi. 



IRELAND.- -Errigal, Donegal ! 



Geogr. Distribution.- -Norway. Sweden. 



55. Cosmarium Garrolense Roy & Biss. 

 (PI. LXVI, figs. 7, 8.) 



Cosmarium Garrolense Roy & Biss. Scott. Desm. 1894, p. 101, t. 2, f . 4 ; 



Schmidle, Beitr. alp. Alg. 1895, p. 351. 



C. latereundatum Roy t Biss. MS. I.e., p. 101 [name only]. 

 C. alpinum (Racib.) De Toni var. Helveticum Schmidle, Alg. Bern. Alp. 



1894, p. 89, t. 6, f. 11 [vide West & G. S. West in Journ. Bot. Mar. 



1895, p. 67]. 



C. alpinum- (Racib.) De Toni var. Garrolense (Roy Biss.) Schmidle in 

 Nnova Notarisia, 1897, p. 66; Lappmark Susswasseralgen, 1898, p. 41. 



Cells rather small, 1-J times longer than broad, 

 deeply constricted, sinus very narrow with a dilated 

 apex ; semicells trmicate-pyramidate, sides upwardly 

 converging and slightly convex, with three to five 

 equal undulations, apex widely truncate but distinctly 

 convex (sometimes obscurely plicated). Side view of 

 semicell subcircular. Vertical view elliptic, ratio of 

 axes about 1 : 1'6. Cell-wall sparsely and delicately 

 punctate. 



Zygospore unknown. 



Length 27-31 //; breadth 20-25 /*; breadth of 

 isthmus 9-11 //. 



ENGLAND.- -Near Ambleside, Westmoreland ! 



SCOTLAND. - - Den of Garrol, Kincardine ; Clova 

 Tableland, Forfar ! (Pot/ cj- Bissett). 



Geoyr. Distribution. --Qermsxiy. Switzerland. N. 

 Sweden. 



We have already shown that C. alpinum (Racib.) De Toni 

 is without doubt a small form of C. undulatum Corda, being 

 identical in size and general outline with C. undulatum var. 

 minutum Wittr. (vide vol. ii ; pp. 149-150). C. Garrolense 

 Roy & Biss. differs from the latter in its widely truncate 

 apex which is without undulations. 



56. Cosmarium Reinschii Arch. 

 (PI. LXVI, figs. 9, 10.) 



Cosmarium sp. Eeinsch, Contrib. Alg. et Fung. 1875, p. 83, t. 18, f. 4. 



C. Reinschii Arch, in Quart. Journ. Micr. Sci., 1876, n.s. vol. vi, p. 109 ; 



