204 
Dictyosphaerium, Néig., 1849. 
"D. ehrenbergianum, Näg. Hinz. Alg., 13,1. ii, E. “Open-air 
tank at Kew, mixed with Spirogyra and Cladophora,” 1889. 
(Massee! cp. — Linn. Soc., vol. xxvii, 1889, 458.) Not 
observed this 
Botryococcus, Kiz., 1849. 
B. Braunii, Kiitz. Sp., 892. Plankton of Thames, August, 1902. 
4. CHLOROCOCCACEA E. 
Characium, Braun, 1847. 
C. Sie ieboldi, Brawn Alg. Unicell., 32, t. 3, f. A., 1-21. Attached 
to a species of Oedogonium, growing on the stonework of the 
fountain in the pond, May, 1902 (active zoospore-formation was 
going on); attached to a water-plant, laboratory tank, August, 
1902. 
C. tenue, Herm. in Rabh. Beitr., 26. Attached to Cladophora 
in tanks of water-lily house, April-September, 1902. 
Chlorococcum, Fries, 1825. 
C. humicolum (Nág.), Rabh. Kr. Fl. Sachs., 137. On old wood, 
Queen’s Cottage Grounds, January, 1902 ; forming a dark green 
oor of the temperate house, 1902; on old wood in bamboo 
garden, Pe 1902. Nearly always together with some Species 
of Ulothri 
C. frustulosum (Carm.), Rabh. Alg., iii., 59. Forming a pulver- 
ulent green coating on rocks in the rockery, March, 1902. 
C. murorum (Grev.), Rabh. Alg. iii, 61. On brickwork in 
tropical fern house (No. 2 anwar, 1902 ; outside walls of 
temperate house, February, 1 
9. PLEUROCOCCACEAE. 
Crucigenia, Morren, 1830. 
C. rectangularis, (Br.), Chod. Lake, September, 1902 (forma 
major ; cells 11-13 p long, 6-9 p wide). 
Actinastrum, Lagerh., 1882. 
in Ófvers. af Kgl. Vet.-Akad. Férhandl., 
A. Hantzschii, Lag. i 
1882. Isolated in water-lily pond, September, 1902 ; isolated in 
plankton of Thames, August, 1902. New for the British Isles. 
Lemmermannia, Chod., 1899. 
od. Alg. Vert. de la Suisse. Rather rare in 
L. emarginata, Ch 
M oxide and water-lily pond, September, 1902. New for the 
ritish 
