26 BRITISH DESMIDIACE^E. 



SCOTLAND. - -Sutherland !, Ross, Inverness!, Aber- 

 deen, Kincardine, Perth!, Argyll, Stirling (Roy fy 

 Bissett]. Harris, Outer Hebrides! In the plankton 

 of Lochs nan Cuinne and R,uar, Sutherland ! ; also 

 plankton of Loch Fadaghoda, Lewis ! 



IRELAND.- -Near G-lenties and Lough Anna, Donegal ! 

 Ballynahiuch, Lakes near Recess, Clifden to Round- 

 stone, Loughs Aunierin and Derryclare, and Loughs 

 east of Lough Bonn, G-alway ! Dublin and Wicklow 

 (Archer). Slieve Donard, Down ! In plankton of 

 small lakes, Clifden to Roundstone, Galway ! 



Geogr. Distribution.- -France. Germany. Austria. 

 Hungary. Gralicia. Italy. Norway. Sweden. Den- 

 mark. Bornholm. Finland. S. Russia. Japan. India. 

 Burma. Singapore. Sumatra (form). Java. Central 

 Africa. Sandwich Isles. United States. Guiana. Brazil. 



C. connatum is generally distributed in Scotland, Ireland, 

 and the western areas of England and Wales, but is decidedly 

 local. It is rarely found among Sphagnum, having* a 

 preference for the margins of lakes where it often occurs 

 among other Desmids around such plants as Isoetes, Utricu- 

 laria, Eriocaulou, etc. 



Var truncatum West. (PI. LXVII, fig. 18.) 



C. connatum var. truncatum West, Alg. W. Ireland, 1892, p. 161, t. 21, f. 16. 



Cells more deeply constricted, with broadly truncate 

 apices. 



Length 105/>t; breadth 75/x; breadth of isthmus 45 /x. 

 ENGLAND.- -Hawkshead, Lancashire ! 

 IRELAND.- -Derryclare Lough, Galway ! 



This variety is well-marked by its increased depth of con- 

 striction and by its broadly flattened apices. We have only 

 observed it once since its first discovery in Ireland. 



/ 



63. Cosmarium pseu do connatum Nbrdst. 

 (PL LXVII, fig. 19-21.) 



Cosmarium pseudoconnatum Nordst. Desm. Brasil. 1870, p. 214, t. 3, f. 17 ; 

 Lund. Desm. Suec. 1871, p. 45 ; West, Alg. W. Ireland, 1892, p. 161 ; 

 Alg. Engl. Lake Distr. 1892, p. 729 ; Eoy & Biss. Scott. Desm. 1894, 



