19 DR. С. S. WEST ON THE ALGAE OF 
April 1st, 1905.— Desmids still dominant, the most abundant species being 
Cosmarium Hardyi; others in great abundance were Staurastrum lepta- 
canthum, 5. longiradiatum, 5. corniculatum and its var. spinigerum, and 
Micrasterias Нат. Peridinium Volzii var. australe was not uncommon, 
but Dinobryon was rare. Melosira granulata still abundant, mostly with 
short filaments possessing the curious spines of var. spinosa, Schrüder *. 
Chrooeoccus limneticus var. subsalsus was not infrequent ; and the Crustacea 
were beginning to be more conspicuous. 
May 6th, 1905.— Reduction in quantity of Desmids and also in number of 
species. The smaller species had almost vanished, but Cosmarium Ната 
and Staurastrum leptacanthum were not uncommon, and Mierasterias Hardyi 
was still abundant. Melosira granulata still fairly common, and the 
individuals of Peridinium Volzi var. australe are much larger, with thicker 
walls and more marked areolation of the plates. No Dinobryon was 
observed. The Crustacea now very evident, forming a relatively large 
amount of the plankton. 
June 3rd, 1905.—Crustacea dominant. Few Desmids present, only odd 
specimens of Mierasterias Hardyi and a few other large species. Very little 
Melosira aranulata. Quantity of Spherocystis Schroeteri. 
July 1st, 1905.—Crustacea dominant, and owing to mass of individuals 
actual bulk of plankton is increasing. — Mierasterias Hardyi the only Desmid. 
Spherocystis Schroeteri quite common. Melosira granulata distinctly scarce. 
Aug. 5th, 1905.—This month the plankton reached its greatest bulk owing 
to the enormous abundance of Crustacea (Daphnia, Bosmina, Cyclops, and 
other genera). Phytoplankton almost wanting. Melosira granulata was 
rare, and a few specimens of Micrasterias Hardyi, Staurastrum victoriense, 
and Desmidium Swartzii were observed. 
Sept. 2nd, 1905.—Crustacea still paramount, and actual bulk of plankton 
little less than in August. Desmids represented by a few isolated specimens 
of Micrasterias Ната. Melosira granulata тате, but the Diatoms were 
further represented by a few fine specimens of Surirella robusta var. 
splendida. The plankton contained quantities of the pollen-grains of Pines. 
Oct. Tth, 1905.— Relative bulk of plankton only about half that obtained 
in August. (Great diminution in numbers of Crustacea, and а plentiful 
admixture of Nauplii among the adults. Desmids rare. Very little Melosira 
granulata, but a few specimens of Navicula bicapitata could always be found. 
Tetraspora lacustris quite common, the colonies appearing to be young, some 
of them having rather a tough integument. 
Nov. 4th, 1905.—The dominant constituents were Chlorophyceæ and 
Diatoms, but plenty of Copepods, Bosmina, and Nauplii were still present. 
Of the Chlorophyceæ, Tetraspora lacustris was most conspicuously abundant, 
* В. Schroder in Ber. Deutsch. Bot. Ges. xv. (1897) p. 373, t. 17. f. 3. 
