138 BIOLOGY OF THE RICHMOND RIVER, 



Casino, on decaying Hydrodictyon (14). 



Cf. Nowakowski, I.e., p.88, T. v., f.6-1 2, T. vi., f.1-5. He gives 

 the size of the mature zoosporangium as, long. 40, lat.25, zoospores 

 diam. 5, dauerspores diara. 18-30 /x. The young zoosporangium 

 is globose, becoming pyriform or ovate with growth: and, at the 

 base, four rugae form, disposed crosswise Occasionally these are 

 found also in very young zoosporangia, in which case the latter 

 are somewhat dome-shaped. The corrugations are not shown in 

 Nowakovvski's figures, probably because his specimens were grow- 

 ing freely in the mucus of Chcetophora; this also accounts for 

 many other differences of growth. In our specimens, growing, as 

 they were, on decayed algal cells, the zoosporangia lie outside and 

 the dauerspores and hyphse inside the cell- wall, being connected 

 by a minute pore. It would appear, therefore, that, in these 

 cases, the zoosporangial cell forms first, pierces the cell-wall of 

 the host, and gives rise to the mycelium and dauerspore within. 

 The dauerspore evidently acts as a reservoir, gradually passing 

 on its contents to the zoosporangium, for when the latter is 

 mature, the dauerspore is always empty and the hyphse atropied. 



Rhizidium SpiROGYRiE, n.sp. (PI. vii., f.7). 



Zoosporangium maturum globosum ; in speciminibus vacuis 

 superne truncatum, oris levissime eversis; (cellulae immaturae 

 ssepe plus minusve ovatse); ad basin petiolo brevissimo instructum, 

 dauersporis nullis. 



Long. = lat. = 10-34 /a. 



Lismore, on decaying cells of Spirogyra maxima {20). 



Quantities of minute growing cells were noted also, from diam. 

 4 /x upwards, globose Very rarely, there is found a minute 

 ( X 3 /x) swelling where the dauerspore should be. 



SCHIZOMYCETES. 



Spirillum volutans. 



In filament-form, and in active and non-motile spirals. The 

 filamentous form looks like an Oscillatoria or Lynghya. It is 

 generally hyaline or very pale blue, and very lively, coiling and 

 twisting until it breaks into short lengths. These remain quies- 



