ON SCOTTISH DESMIDIE/E 175 



EUASTRUM (Ehr.\ Ralfs. 



1. E. Aboense, Elfv. Rare, or overlooked. Aberdeen on Ben 



Muich Dhui, above Loch Etchachan. 



2. E. affine, Ralfs. General, not abundant. 



3. E. ampullaceuin, Ralfs. Not very common. Sutherland, Ross, 



Inverness, Aberdeen, Kincardine, Forfar, Perth, Argyle, 

 Arran, Fife. Conjugated with zygospores in Aberdeenshire, 

 in moraine pools near Cambus-o'-May. The zygospores 

 are globular, with numerous short, conical, acute spines. 

 Diameter without spines, 54-60^ length of spine 6.4 /i. 



4. E. ansatum, Ralfs. General and abundant. Vars. sublobatum 



w\&pyxidatum, Delponte, are common, but scarcely deserve 

 special notice. Found conjugated with zygospores in 

 Aberdeenshire, near Turriff, by Mr. W. Anderson. They are 

 globular, with numerous short, stout, abruptly sharp-pointed 

 spines. Diameter without spines, 38. 4^; length of 

 spine, 6.4/./,. 



5. E. binale (Turpin.), Ralfs. General and abundant. Extremely 



variable. The following forms from Ralfs are common, 

 and seem pretty constant. Their zygospores are much 

 wanted. 



(a) Forma minuta, Lund. (Ralfs, " Br. Des.," t. xiv. 8 a). 



(/>) Forma (Ralfs, I.e. 8/>). 



(f) Forma (Ralfs, I.e. 8f, d). 



(d) Forma (Ralfs, I.e. 8e), etc. 



6. E. crassicolle, Lundell. Rare. Ross Poolewe ; Aberdeen 



Presswhin and Bogwartle in Cromar, Colonel's Bed in 

 Glen Ey ; Forfar Canlochan ; Perth Rannoch, Craig-an- 

 Lochan ; Kirkcudbright New Galloway. 



7. E. crassuni (Breb.), Lund. General. 



8. E. cuncatum, Jenner. Not common. Sutherland, Ross, Inver- 



ness, Aberdeen, Kincardine, Forfar, Perth, Arran, Kirkcud- 

 bright. 



9. E. declive, Reinsch. Abundant. Zygospores are not uncom- 



mon. 



10. E. dentieiilatum, Gay. General. 



11. E. didelta, Ralfs. General. With zygospores, at Dalwhing 



near Aboyne. They are globular, very thick-walled ; spines 

 not numerous, short, stout, and blunt. Diameter without 

 spines, 73. 6 /x; length of spine, 12. 8 ^. 



12. E. divarieatum, Lundell. Very rare. Argyle in Glen Coe. 



