56 BRITISH DESMIDIACE^:. 



Zygospore unknown. 



Length o'2-4(3,i; breadth 9'5-10/t. 



ENGLAND. Old Cote Moor, West Yorkshire !, in 



bogs. 



As in the previous species the cell-sap of this plant is 

 coloured violet or purple hy phycoporphyrin. M. p-nr^nrriini 

 is a free-swimming species and the chloroplast usunlly con- 

 tains two pyrenoids. Sometimes, as in other species of this 

 genus, the chloroplast is obscured by hir^e globules of an oily 

 reserve material. 



0. Mesotsenium Endlicherianum TvV. 



& 



(PI. IV, figs. 20, 21.) 



Mesotsenium Endlicherianum Nag. Gatt. einz. Alg. 1849, p. 109, t. (5 11 ; 

 Kirchn. Alg. Schles. 1878, p. 134 ; Wolle, Desm. U.S. 1884, p. 32, t. 3, 

 f. 11 ; Eoy & Biss. Scott. Desm. 1894, p. 61 (sep.) ; West & G. S. West, 

 Some Desm. U.S. 1898, p. 281 ; Alg. N. Ireland, 1902, p. 19 ; Alga-fl. 

 Yorks. 1900, p. 42 ; Nordst. Index Desmid. 1896, p. 118. 



Palmoglcea Endlicheriana Eabenh. Flor. Evirop. Algar. Ill, 1868, p. 116. 



Cells cylindrical, 3-4 times longer than their dia- 

 meter, apices broadly rounded; chloroplast an axile 

 plate, pyrenoids one in each semicell. 



Zygospore unknown. 



Length 25-27 n ; breadth 8-9-5 /*. 



ENGLAND.- -W. and N. Yorks! Cheshire (Roy). 

 Leicester (Roy). Cornwall ! 



WALES. Bog below Llyn Idwal, Glyder Fach (at 

 2,200 ft.), Glyder Fawr (at 2,600 ft.), Llyn Cwlyd, 

 Llyn Pencraig near Bettws-y-coed, Carnarvonshire ! 



SCOTLAND. Sutherland, Ross, Inverness, Aberdeen, 

 Kincardine, Forfar, Perth, Stirling, Renfrew (Roy fy 

 Bissett). 



IRELAND. Near Gweedore and near Glenties, Done- 

 gal! Bog near Lough Neagh, Londonderry ! 



Geogr. Distribution. Germany. Switzerland. Ga- 

 licia and Austria. S. Russia. Australia. W. Indies. 

 United States. 



This species sometimes occurs in quantity in boggy pools 

 or at the boggy margins of mountain lakes and tarns. 



