205 
Tetrastrum, Chodat, 1895. 
T. staurogeniaeforme (Lemm.) Chod. Alg. Vert. de la Swisse 
Middle tank of water-lily house, July, 1902. 
Scenedesmus, Meyen, 1829. 
B. acutus, Meyen in Nov. Act., xiv. 2, 775, n. 4, t. 
f. 32. Laboratory tank, May, 1902 ; lake, June, 1902 ; kh 
of Thames, August, 1902. 
Var. obliquus, Rabh. Alg., iii, 64. Same localities as the 
species ; also moat, July, 1902. 
Var. dimorphus, Rabh. Alg., iii., 64. Side tanks of water-lily 
house, June, 1902 ; lake and water-lily pond, September, 1902. 
rvatus, Bohlin, Algen der Erst. Regnell’schen | Exped. 
asin) 23 (sep.), t. I., f. 41-44, et 52. Lake and pond, September, 
genia rectangularis, which occurred in the same water together 
with Scen. curvatus. lt seems possible that both are only forms 
of the same species, as intermediate stages were observed. 
S. quadricauda, Bréb. Alg. Falais. 66. Common in all the 
artificial waters, in the plankton and otherwise 1902; moat, May, 
1902; plankton of Thames, August, 1902 ; a glass vessel in 
the Herb. puit) March, 1902; Visitor: tik; July, 1897 
Massee !). 
Var. abundans, Kirchn. Algenfl. Schles., 98. Middle tank of 
pecus house, July, 1902 ; lake, September, 1902. 
Bystrix, Lagerh. Pediastr. Protoc. och Palmellaceer, 1882, 
E t. ii. aTe 18. Water-lily pond, September, 1902. 
Coelastrum, Näg., 1849. 
C. microporum (Ndg.), Braun As Unicell., 10. Lake and 
water-lily pond, June-September, 1902. 
Kirchneriella, Schmidle, 1893. 
K. contorta (Schmidle), Bohlin. Isolated emange Cladophora in 
pond, September, 1902. New for the British Isl 
K. lunaris (Kirchn.), Moeb. Plankton of Thames, August, 1902. 
obesa (West), Schmidle. Middle tank of water-lily house, 
July, 1902. 
Rhaphidium, Kiitz., 1845. ; 
R. polymorphuin, Fresen. in Abh. d. Senckenb. Nat. Gesellsch., ii., 
199. 
Var. € Rabh. Alg. 2 iii, 45. Isolated amongst other 
Algae in side-tanks. of water lily house, ii icine 
1902; lake, mesas 130 
