BY G. I. PLAYfAIft. 849 



Cf. Chodat, Bull, de I'Herbier Boissier, 1897, p.292, T. ix.; 

 Alg. vertes, p.11'1, f..o3. I have never been able to see any 

 difference between Gloeocystis and Sphcerocystis, except that 

 coenobia of the latter run to greater dimensions. In regard to 

 the size of the cells, Sph Sch^'iHeri occupies exactly an inter- 

 mediate position between Glveocystis vesiculosa and G. gi(jai<; and 

 when its large cells divide into groups of 8, they form coenobia 

 which are Gl. vesiculosa pure and simple, as figured by Nageli, 

 Gatt. einz Alg., T. iv f, fig.l, the normal form of the species, 

 and, indeed, the only one I have ever noted. 



Var TETKAKDuiCA, n.var. (PI. lix , f.ll ). 



CellulBS intra coenobium tetraedrice ordinatae. 

 Ccenob. diani. 44-45; cell. diam. 9-12//.. 

 Sydney Water (80, 81); Coogee; Botany. 



This form is not uncommon; the cells are close together, and 

 and obviously arranged tetraedrically. 



Genus Glceocystis Nageli. 

 Gl(Eocystis vesiculosa Nag. (PI. lix., f.l2). 

 Ccenob. diam 14-60; cell. diam. 3-6/v,. 

 Auburn; Collector; Sydney Water (63). 



Cf. Nageli, Gatt. einz. Alg., T. iv f, fig.l. He gives tlie cells 

 as spherical or ellipsoid; in those specimens I have met with, the 

 cells were always spherical. 



Glcecystis gigas (Kutz.) Lag. (PI. lix, f. 13, 14). 

 Ccenob. diam. 30-60; cell, diam, 10-20/x. 

 Auburn; Collector, Murray's Lagoon; Botany (71). 

 Syn., ProtocoGcus giyas Kutz., Glosocapsa ampla Kiitz., Glceo- 

 cystis ampla Rabh., Chlorococcum gigas (Kiitz.) Grun. 



Glceocystis australis, n.sp. (PI. lix., f.l5). 



Coenobium globosum vel subglobosum, cellulas ovales 4, 8, 16 

 includens. 



Coenob. spheer. diam. 42-60, subglob. long. 20-34, lat. 15-20; 

 cell. long. 12-18, lat. 8-1 2/x. 



Auburn; Guildford (23). 



