THE FRESHWATER PLANKTON OF THE SCOTTISH LOCHS. BLY 
*" 
a el 
os 
No. 3. 1, Stawrastrum Arctiscon; 2, St. gracile; 3, St. jaculiferum ; 4, Xanthidiwm antilopeum ; 5, 
herocystis Schroeterti; 6, Tabellaria fenestrata, var. asterionelloides; 7, Ceratiwm hirundinella; 8, 
rea cochlearis. 
No. 4. 1, Micrasterias pinnatifida; 2, Xanthidium antilopwum; 3, Staurastrum dejectum; 4, St. 
erum; 5, St. gracile; 6, Mougeotia, sp.; 7, Spherocystis Schroeterit ; 8, Microcystis, sp.; 9, Ceratiwm 
ella; 10, C. cornutum ; 11, Anurzxa cochlearis, 
o. 5. 1, Micrasterias furcata ; 2, Staurastrum Brasiliense, var. Lundellit; 3, St. Ophiura; 4, St. 
, var. cyathiforme; 5, St. jaculiferum; 6, St. anatinum; 7, Hudorina elegans; 8, Ceratiwm 
ndinella ; 9, Notholca longispina; 10, Nauplius larva. 
9. 6. 1, Xanthidium antilopeum ; 2, Staurastrum Ophiura; 3, St. anatinum ; 4, St. jaculiferum ; 5, 
spinum, var. altum; 6, Spherocystis Schroeterti ; 7, Asterionella gracillima ; 8, Ceratium hirun- 
; 9, Anurexa cochlearis ; 10, Polyarthra platyptera ; 11, Notholca longispina. 
= 
Puate 4. 
Photomicrographs of special objects in the plankton of Loch Fadaghoda, Lewis, Outer Hebrides. Nos. 
and 6 x 200; No. 4 x 400. 
o. 1. 1, Merismopedia xruginea ; 2, Micrasterias radiosa. 
No. 2. 1, Staurastrum grande; 2, Cosmarium moniliforme ; 3, Ludorina elegans (young colony) ; 4, 
” m hirundinella, be 
B No. 3. Ineffigiata neglecta ; a typical colony from the plankton. 
No. 4. Botryococcus protuberans, a small colony. 
No. 5. 1, Desmidinm coarctatum, var. cambricum; 2, Staurastrum jaculiferum; 3, Ceratiwm 
cS 
6. 1, Staurastrum Ophiura (semicell in vertical view) ; 2, Ceratium hirundinella. 
Puate 5. 
tomicrographs of plankton from various lochs. x 100. 
1. Material from Loch Tay, Perthshire. 1, Stawrastrum paradoaum; 2, St. paradoxum, var. 
3, St. cuspidatum, var. maximum; 4, Asterionella formosa; 5, Celospherium Kiitzingianum ; 
dinium, sp.; 7, Notholca longispina ; 8, Bosmina, sp. 
No. 2. Material from Loch Tay, Perthshire. 1, Cosmarium abbreviatum, var. planctonicum; 2,” 
trum paradorum; 3, St. paradoxum, var. longipes; 4, St. jaculiferum; 5, Tabellaria fenestrata ; 
ella formosa; 7, Celospherium Kiitzingianum ; 8, Notholca logispina ; 9, Anurxa cochlearis, 
o. 3. Material from Loch Rosque, Ross. 1, Staurastrum paradorum; 2, St. curvatum; 3, St. 
rum, forma biradiata; 4, Arthrodesmus triangularis, var. subtriangularts ; 5, Mougeotia, 2 sp.; 6, 
ra pulchella ; 7, Asterionella formosa. 
4. Material from Loch Laxadale, Harris, Outer Hebrides. 1, Stawrastrum Ophiura; 2, Xanthidium 
m, var. Hebridarum ; 3, Anabena circinalis ; 4, Dinobryon elongatum ; 5, Anurexa cochlearis. 
5. Material from Loch Diracleet, Harris, Outer Hebrides. 1, Stawrastrum jaculiferum; 2, St. 
3, St. brevispinum, var. altum; 4, Tabellaria fenestrata; 5, Notholea longispina; 6, Polyarthra 
ar; 1, Anurea cochlearis. 
6. Material from Loch Laxadale, Harris, Outer Hebrides. 1, Hyalotheca neglecta; 2, Xanthidium 
m, var. Hebridarum ; 3, Anabena circinalis; 4, Tabellaria flocculosa; 5, Ceratium hirundinella ; 
za cochlearis. 
Puate 6. 
Tn this Plate and in Plate 7 the following letters are used :— 
a, aw = front view. 
b = vertical view. 
¢ = side (or lateral) view. 
Fig. 1. Gonatozygon monotenium, De Bary, var. pilosellum, Nordst. x 520. 
oe 2: ns aculeatum, Hastings. x 520. 
TRANS. ROY. SOC. EDIN., VOL. XLI. PART III. (NO. 21). 76 
