178 ANNALS OF SCOTTISH NATURAL HISTORY 



Mr. Archer, 'about the year 1866. He sent it to me with 

 beautiful drawings in 1874. In the following year he 

 gathered it in Argyle, and we found it in Aberdeen. It is 

 very local and rare in this country. 



7. S. apiculatum, Breb. General, but scarce. With zygospores, at 



Slewdrum in Aberdeen. 



8. S. Arachne, Ralfs. Distribution peculiar ; all but confined to 



Deeside, where it is not uncommon. Aberdeen Upper Pow- 

 lair, Slewdrum, Forest of Birse, near church of Birse, south 

 of Birsemore, Craigendinnie, Steps, Glen Tannar, Dalwhing, 

 Tomachar, Culblean, south of Loch Kinord, Dalbagie, Loch 

 Ullachie, Castleton in Braemar, and Glen Clunie; Kincardine, 

 Nigg, Crathes, Curran ; Argyle Glen Coe. 



9. S. Arctiscon (Ehr.), Ralfs. Very rare. Aberdeen Birsemore 



Loch and Dalbagie; Argyle --in Mull near Tobermory 

 (1878). 



i o. S. arcuatum, Nordst. - - Very rare. Aberdeen pool beside 

 Loch Dawan, Dalbagie, and in Glen Clunie. 



11. S. aristifennn, Ralfs. Not common. Inverness, Aberdeen, 



Kincardine, Perth, Dumbarton. 



12. S. arniigcruiu, Breb. ("Liste," 1856, S. pseudofurcigerum, Reinsch, 



"Acta Senckenb," 1867, and "Die Algenflora," 1867). 

 Not common. Inverness, Aberdeen, Kincardine, Forfar, 

 Perth, Stirling, Arran. 



With zygospores, at Heughhead, near Aboyne. They are 

 globular, with numerous spines, which are broad at the base 

 and taper to a fine, slightly bifid apex. Diameter, exclusive 

 of spines, 41 /A ; length of spine, i 2 //, (Plate IV. Fig. i 2). 



13. S. ArneUii, Boldt. 



(3 inornatum, n. var. Extremely rare. The only difference 

 consists in the granules being scattered. Aberdeen 

 near Alford (Mrs. Farquharson of Haughton). 



14. S. aspemm, Breb. Not common. Sutherland, Ross, Aberdeen, 



Kincardine, Forfar, Perth, Fife. 



1 5. S. aversum, Lundell. Very rare. Aberdeen near Aboyne ; 



Kincardine at Cammie. 



1 6. S. Avicula, Breb. General. 



Zygospores have been seen in the Feugh, at Heughhead, 

 Kincardine. (Plate IV. fig. 1 1 is probably a form of this 

 species with zygospore.) 



17. S. barillare, Breb. 



/3 obesuin, Lundell. Extremely rare. Aberdeen in a 

 small pool at the south end of Loch Dawan. 



