242 ANNALS OF SCOTTISH NATURAL HISTORY 



g. D. minutum, Ralfs. General, but scarce. 



10. D, nobile (Richter), Lund. -- Rare. Ross-- Poolewe ; Aber- 



deen Cambus-o'-May ; Kincardine moraine pool near 

 Bishop's Dam and Dalbrake in Strachan; Argyle near 

 Kingshouse. 



11. D. rectum (Delp.), Wolle. General. 



12. D. Trabecula (Ehrb.), Nag. Not common. Ross Garve ; 



Inverness Loch Ruthven ; Aberdeen various localities; 

 Kincardine - - Blackball, Curran, Muchalls ; Perth Glas 

 Mhoel ; Arran Corrie, Glen Sannox. 



13. D. tridentuhim, Wolle, 1884. Rare. Ross Poolewe; Inver- 



ness Brin ; Argyle head of Glen Coe and in Mull. 



In July 1883 one of the present writers published a list 

 of Desmids found in Mull, in the " Scottish Naturalist." 

 The gathering contained a number of examples of this 

 species, or of something very near it. The specific name 

 sceptrum, which had been given by Kiitzing to Baculum, was 

 resuscitated, and applied to this species as a suitable name. 

 If tridentuhim was not published by Wolle previous to its 

 appearance in his " Desmids of the United States," our 

 name sceptrum will claim priority. Scottish and Irish speci- 

 mens are slightly more prominently swollen at the base, 

 taper more towards the apex, and are quite smooth, not 

 roughly punctate, or even finely granulated, as in South 

 American examples in our possession. 



Length, 280-320 /A; breadth, constrict, 14/11; basal swell- 

 ing, i6//,; close above, n-13//,; close to apex, 6^-8 ^; 

 apex, 8-9! fj.; length of tooth, 2\ p. 



14. D. truncation, Breb. General. 



Var. granulatum, West. Very rare. Perth Ben Laoigh 

 (Mr. W. West). 



TETMEMORUS, Ralfs. 



1. T. Brebissonii (Menegh.), Ralfs. General. 



/3 turgidus, Ralfs. Not uncommon. 

 j minor, De Bary. Common. 



2. T. granulatus (Breb.), Ralfs. Abundant. 



Has been collected with zygospores at Fyvie and Birse- 

 more in Aberdeen, and in Glen Dye in Kincardine. 



3. T. lavis (Kg.), Ralfs. General. 



Collected with zygospores in Aberdeen in Whitestripes 

 Moss, and Heughhead near Aboyne ; and in Kincardine 

 at Cammie, in Strachan. 



4. T. minutus, De Bary. Not uncommon on wet rocks. 



