172 ANNALS OF SCOTTISH NATURAL HISTORY 



2. S. excavatum, -Ralfs. General. Frequently conjugated, especi- 



ally among stones in the margins of streams. 



/3 Wallichii, Jacobs. Probably not uncommon. Inver- 

 ness, Aberdeen, Kincardine. 



y Wallichii has been observed on Deeside, and is 

 probably common. 



3. S. gmnulatum, Roy and Bisset. Widely distributed, but not 



common. Sutherland, Inverness, Aberdeen, Kincardine, 

 Forfar, Perth, Argyle. 



4. S. secedens, De Bary. Very rare. Aberdeen at Slewdrum in 



Birse, Loch Dawan, and Mosston Moor in Cromar. 



5. S. vertebratum (Breb.), Ralfs. Not common. Aberdeen, 



Kincardine, Forfar, Perth. 



ONYCHONEMA, Wallich. 



1. O. filiforme, Ehr. (Sfharozosma, Aut.) Not common. Ross- 



near Strathpeffer ; Inverness Lochs Ruthven, Aschie, and 

 Coire, etc., near Brin ; Aberdeen and Kincardine have 

 numerous localities. 



2. O. Iccve, Nord. Extremely rare. Found once. Aberdeen 



by the side of the old road from Aboyne to Kincardine 

 O'Neil, about a mile from Aboyne. 



3. O. Nordstedtiana, Turner. Not common. Probably occurs 



more frequently than its near relative O. filiforme ; but its 

 separate distribution was not noted till recently. 



MICRASTERIAS, Ag. 



1. M. americana (Ehr.), Ag. Rare. Aberdeen Scotston Moor, 



Powlair, south of Birsemore, Slewdrum, Morven, Lochnagar, 

 corrie of Loch Ceanmhor ; Kincardine Glen Dye and 

 Clochnaben ; Forfar Lundie Bog near Menmuir ; Perth- 

 Glen Shee and Glas Maol. 



ft Ralfs. Very rare. Aberdeen - - Corrie of Loch 



Ceanmhor ; Kincardine Crathes, and about Cam- 



mie in Strachan. 



2. M. angulosa, Hantz. Not common. Sutherland, Ross, Inver- 



ness, Aberdeen, Kincardine, Forfar, Perth, Argyle. 



Conjugated at Slewdrum on Deeside. Zygospore large, 

 globose ; spines stout, bi-, tri-, and quadri-furcate at their 

 apices, and not very numerous. Diameter, without spines, 

 1 1 4-1 1 6 /z; length of spine, 32/z (Plate IV. fig. 2). 



3. M. conferta, Lundell. Rare. Inverness Glen Urquhart ; 



Aberdeen Upper Powlair in Birse, Birsemore Loch and 

 Dalwhing near Aboyne, pool north of Loch Dawan, and 



