206 
Var. falcatum, Rabh. loc. cit. Amongst other unicellular 
Algae on underside of leaves of Ne/umbium, water-lily house, 
June-September, 1902 (mihi !), laboratory tank, July, 1897 
(Massee 1). 
Var. sigmoideum, Rabh. loc. cit. Middle tank of water-lily 
house, TU. 1902. 
R. pyrenogerum, Chod. Alg. Vert. de la Suisse. 
Var. faleiforme, Chod. Isolated in plankton of Thames, 
August, 1902. Probably only a form of R. fasciculatum, 
possessing pyrenoids. 
Palmella, Lyngb., 1819. 
P. mucosa, Kiitz. Phyc. Gen., 172. On the stone-work of the 
louxthin in the pond, April- “May, 1902 (? erem a resting-stage 
of Chlamydomonas, or an allied genus); forming a greenish, 
slightly arent stratum on the pebbles in Mk 1 and 8, June- 
September, 1902 (?) 
Gloeocystis, Näg., 1849. 
G. ampla (Kiitz.), Rabh. Alg., , 29. With other Algae on 
outside walls of a Sear house, Kp 902. 
G. rupestris (Lyngb.), Rabh. Krypt. Flor. Sachsen, 128. On 
the rocks in the bamboo garden, March, 1902. 
nata (Huds.), Näg. Hinz. Alg., 65, F. Forming 
little var an masses d ith hor Ned 
Algae on pue ius of Aroid house (No. 1), June-September, 
1902. As far as I am aware, this xe e has not pietiiealy been 
described for the British Isles. 
Polyedrium, Näg., 1849. 
P. tetraedricum, Nig. Kinz. Alg., 84, t. iv., B., f. 3. Water-lily 
house tanks, June, 1902. 
P. hastatum, Reinsch, p Frank. 11, t. 5, f. 3. Middle 
tank of water-lily house, July, 1902 ; pond, September, 1902. 
regulare (Kiitz.), Chod. v Vert. de la Suisse. Middle 
TE of water-lily house, July. 1902. 
Forma bifurcatum, nob. Spines bifurcated at the ends. 
Same locality as the species. In my opinion, the two last- 
icum, Nàg. A large number of intermediate forms, not 
corresponding absolutely with the Mgr deese of any of these 
species, was met with. Both have, as far as I am aware, not 
yet been described for this country. 
_ *P. (Tetraédrom) longispinum (Perty), Rabh. Alg. Eur., iii., 62. 
x one loc. cit.) 
Hrpponphaese, De Bary, 1858. 
E. viridis, De Bary Conj., 56, t. viii., f. 26, 27. Laboratory tank 
(Massee D); plankton of [ee lily pond, May, 1902, isolated 
mihi !). 
