ON SCOTTISH DESMIDIE^E 253 



20. P. phymatosporum, Nord. Very rare. Kincardine on a wet 



rock near Mill of Muchalls, with zygospores. 



21. P. polyinorphum, Perty. Not uncommon. Shetland, Suther- 



land, Ross, Inverness, Aberdeen, Kincardine, Forfar, Perth, 

 Stirling, Argyle, Arran. 



22. P. Ralfsii, De Bary (P. minutum, Cleve; certainly not Docidium 



minutiim, Ralfs). Somewhat rare. Sutherland near Loch 

 Inver ; Ross abundant at Poolewe ; Inverness in Skye 

 near Loch Coruisk ; Aberdeen head of Glen Tannar ; 

 Forfar Glen Clova, and Clova Tableland; Perth --in 

 Rannoch ; Arran Glen Sannox, Glen Ranza, and Goatfell. 



23. P. Royanuni, Turner ("Algae Aquae Dulcis Indiae Orientalis," 



Stockholm, 1892). Very rare. Perth near Loch Earn 

 (Mr. W. B. Turner). 



24. P. rufescens, Cleve (P. rnfo-pellttiini, Roy, 1877). Not 



common. Inverness, Aberdeen, Kincardine, Perth, Argyle. 



25. P. spinospermum, Joshua. Probably common. Inverness, 



Aberdeen, Kincardine, Stirling, Argyle, Renfrew. 



26. P. spirostriolatuni, Barker. Not common. Ross, Inverness, 



Aberdeen, Kincardine, Perth, Dumbarton, Argyle. 



27. P. truncatum (Breb.), Ralfs. Not rare. Sutherland, Ross, Inver- 



ness, Aberdeen, Kincardine (with zygospores at Muiryhaugh), 

 Perth, Argyle, Arran. 



MESOT&NIUM, Nag. (PALMOGLCEA, Kiifz.} 



1. M. chlamydosporuin, De Bary. Not uncommon. Ross, Inver- 



ness, Aberdeen, Kincardine, Perth. 



2. M. Endlicherianum, Nag. Common. Sutherland, Ross, Inver- 



ness, Aberdeen, Kincardine, Forfar, Perth, Stirling, 

 Renfrew. 



3. M. de Greyii, Turner. Not common. Inverness Braeriach ; 



Aberdeen -Tough, Glen Derry, and "Colonel's Bed"; 

 Argyle Kyles of Bute. 



4. M. macrococcum, Ktitz. (M. Braunii, De Bary). Common. 



Ross, Inverness, Aberdeen, Kincardine, Forfar, Perth, 

 Renfrew. 



5. M. micrococcum (Kiitz.), Kirch. Rare' or overlooked. Inverness 



on Cairngorm ; Aberdeen Dalbagie. 



6. M. violascens, De Bary. Not common. Inverness, Nairn, 



Aberdeen, Forfar, Perth. 



