z 211 
O. subfusca, Vawch. Con ;, 193, t. 15, f. 5.- On stonework of 
fountain i in pond, June, 
0. aerugescens, Drumm. es Nat. Hist., 1838, i, 1. Mingled 
with Ulothrix — on the rocks in "the temperate house 
pools, March, ; on rocks in Nepenthes house, forming an 
tes blackish slum, March, 1902; Victoria regia tank, June, 
0. te esl Ag. Syst. Alg., 60. On damp ground near laboratory, 
January, 1902. Also found in Bot. Gardens, Regent's Park 
(ep. Bennett, loc. cit.). 
0. limosa, Ag. Syst. Alg., 66. Moat, May, 1902. Also found in 
Botanic Gardens, Regent's Park (Bennett, t, loc. cit.) According to 
W. and G. § t (Algal Flora 7 Yorkshire, 1901) this is 
synonymous with 0. Frühlichii, Küt. 
O. irrigua, Kiitz. Phyc. Gen., P On the wall of a pit, 
Naiiba , 1901. 
O. nigra, Vauch. Conf. 192, t. 15, f. 4. Mingled with O. 
ket in laboratory tank, May, 1902 ; in dark steel-blue or 
almost black masses, attached to D yriophyllum all over the lake, 
Biber bor, 1902; also very abundant in the water-lily pond, 
September, 1902. It here forms a rae ua flaky covering all 
w 
b 
ontaining air internally and formed externally of the densely 
irte dvin filaments. These collapse at once when taken out of 
the water. 
*0. chalybea, Mert. in Jurg. Alg. In tank (Massee !). 
0. Frohlichii, Kiitz. fae Gen., 189. On earth of flower-pot in 
pit No. 134., January, 1902 ; Ae at ue pools, May, 1902 ; 
forming a blackish Stratum on the mud in Victoria regia tank, 
lack, sli 
stratum. I have -— informed that this Alga does considerable 
harm to the you g plants, especially to the prothallia ; also on 
the ashes and diat in the palin house, September, 1902. 
Phormidium, K7itz., 1843. 
P. smaragdinum, Kiitz. Tab. Phyc., i., 35, t. 49, f. vi. ing a 
dirty green rur ra hp on eg sides of a tank, eee 
hot water, in No. 5, March, 1902; on walls in pit of trop ica] fern 
house, September, 1902. eo den for the British Isles. 
Microcoleus, Desm., 1823. 
M. chthonoplastes, Thur. in Ann. Sci. Nat., 1875, 377. En- 
tangled ainongst other Algae on the banks of ‘the lake, January, 
1902 ; brickwork in private grounds, March, 1902 ; on the ground 
among moss, Herb. Dptmt., (Massee !). 
rrestris, Desm. Pl. Crypt. Exs., i. No. 55. On moist 
ground amongst Vaucheria, bamboo garden, March, 1902. i 
13757 : 02 
