248 ANNALS OF SCOTTISH NATURAL HISTORY 



Rare. Aberdeen Slewdrum, and Upper Powlair in 

 Birse : Kincardine Cammie, Kerloch, Muiryhaugh, and 

 Dalbrake ; it is also found in North Wales, and in the west 

 of Ireland. 



44. C. pseudodiance, Roy. (Desmids of the Alford District, " Scottish 



Naturalist," 1890, p. 199.) 



Resembles Diane?, as given by Ralfs, in form and colour, 

 arrangement of chlorophyl, starch granules, and moving 

 granules ; but differs in being much smaller, in the outer 

 curve being an arc of a larger circle, and in the inner curve 

 being almost straight for a short distance on each side of 

 the middle. Frond quite smooth, with a single suture at 

 the centre. Tips slightly thickened with an apparent notch 

 on the outside, as in C. Diana. Fourteen to twenty times 

 longer than broad. Length (tip to tip), 192-253 /^ ; breadth, 

 12-14 /*; do. at tip, 2-3 p. (Our Plate I. fig 4.) 



We have had this pretty little species under observation 

 many years, and find it maintaining its characteristics with 

 perfect constancy, whether it is collected in the north-east of 

 Scotland, or in the west of Ireland. We have not been so 

 fortunate as to find it conjugated. Not common. Ross 

 near Tain ; many localities in Aberdeen, Kincardine, Forfar, 

 and Perth ; Argyle near Kingshouse. 



45. C. pusillum, Hantzsch. Rare. Ross at Achnasheen ; Aber- 



deen- Auchterless, Longside, Towie, Whitely near Alford, 

 Birse, and Birsemore ; Kincardine Loch of Park, Clunie, 

 Cammie; Perth at Buchanty ; Argyle near Tobermory 

 in Mull. 



ft major, n. var. Very rare. On wet rocks. Similar to 

 the type, but about twice as large ; smooth and 

 colourless ; six times as long as broad. Length, 

 96-100 /j, ; breadth, 16 /j. ; do. of obtuse, rounded 

 end 7 //,. Aberdeen " Break Neck Fall " at the 

 head of Glen Callater, and in the Corrie of Loch 

 Kandor; Forfar at the "Reeky Linn" on the Isla. 



46. C. Ralfsii, Breb. - - Rare. Ross near Falls of Connon ; 



Aberdeen New Pitsligo, Bourtie, Corbie Loch, Scotston 

 Moor, Cornhill, Springhill and Hazelhead near Aberdeen, 

 Slewdrum in Birse ; Kincardine at Tony ; Forfar near 

 Menmuir ; Argyle near Kingshouse. 



47. C. regulare, Breb. Very rare. Argyle near Kingshouse. 



48. C. rostratum, Ehr. General ; conjugation not uncommon. 



49. C. Scoticum, W. B. Turner (Desmid. Notes, in the "Naturalist," 



Nov. 1893). "Frond long and narrow, for about fths 



