PERIODICITY OF THE PHYTOPLANKTON OF SOME BRITISH LAKES. 421 
Dec. 10th, 1908. Temp. of water 45? Е. (— 72? €.). Material contained 
a large amount of fine detritus. Few Desmids and few Diatoms present. 
Most probably this collection was improperly obtained. 
Jun. 22nd, 1909. Temp. of water 41° Е. ( = 5° C.). Very dirty material, 
similar to previous collection. 
TABLE OF PHYTOPLANKTON FROM осн Earn, 
m 1908, | Dec. 1908. | Jan. 1909. 
SPECIES 60? Е. | 45°F, | 41°R, 
(—15:59 C.) (=Т'З° С.) | (=5° С.) 
Chlorophycee. 
(Edogonium sp. (sterile) ..................... eee r 
Spirogyra sp. (sterile) |. rr 
Cosmarium abbreviatum, Racib., var. planctonicum, W. & G. В. e " rr 
| West 
,, granatum, Bréb. |... eese sss ... m rrr 
| Staurastrum cuspidatum, Bréh., var. maximum, West............... сс r r 
jaculiferum, West, forma biradiata. o...on r rrr rrr 
lunatum, Ва в... т 
брот ОО planum, (Wolle) nob. ssassn: отт 
Nephrocytium lunatum, West... TM rr 
Dictyospherium pulchellum, Wood | ..................... е К: 
| Spherocystis Schroeteri, Chodat ............ sees sees rrr m rrr 
| 
| Bacillariez. 
| Tabellaria fenestrata, (Lyngb.) Кіа. eese rrr 
" Jlocculosa, (Roth) Каф... seem r bee rr 
| Synedra Aeus, (Kütz.) Grun. оа r 
| » Ulna, (Nitzsch) Ehrenb. .... sees | rr rrr 
| Eunotia lunaris, (Ehrenb.) Grun. |... sese r 
| Gomphonema intr icatuin, Kütz, иен ne r 
| Vanheurckia rhomboides, Bréb., var. saxonice, (Rabenh.) r 
| West 
| Cocconema cymbiforme, Ehrenb, п.е r 
| Surirella biseriata, ВгёЪ.. иене nennen r 
| Myxophyces. | 
Oscillatoria Agardhii, Gomont.......... sess | r 
| Cælospherium Kiitzingianwit, Жад. о sese eec r | rr 
Groinphospheria lacustris, Сода... | rrr 
Aphanothece nidulans, Richter, var. endophytica, var. n. ......... e | rr | rr 
| | | 
Peridiniez. | 
‚ Ceratium Hirundinella, О. Е. Müller | .................. "ME c 
Peridinium Willei, Huitf.-Kaas lees | rr 
It is to be regretted that the collections from Loch Earn were not much 
more complete, as it is impossible from the available material to draw any 
conclusions regarding the periodicity of the phytoplankton. 
LINN. JOURN.—BOTANY, VOL, XL. 2G 
