ON SCOTTISH DESMIDIEiE 175 



EUA STRUM (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. ampullaceum, 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 /x; length of spine 6.4 //. 



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



and pyxidatui/i, Delponte, are common, but scarcely deserve 

 special notice. Found conjugated with zygospores in 

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

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

 spines. Diameter without spines, 38.4 /x; length of 

 spine, 6.4 [x. 



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. Zd). 



(b) Forma (Ralfs, I.e. Sb). 

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

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



6. E. erassieolle, 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. crassum (Breb.), Lund. — General. 



8. E. euneatutit) Jenner. — Not common. Sutherland, Ross, Inver- 



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

 bright. 



9. E. dee/n'e, Reinsch. — Abundant. Zygospores are not uncom- 



mon. 



10. E. denticu latum, (lay. — General. 



11. E. didcltd, Rails.— ( leneral. With zygospores, at Dalwhing 



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

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

 spines, 73.6/4; length of spine, ij.S/<. 



12. E. divarication, Lundell. — Very rare. Argyle — in Glen Coe. 



