ALGOLOGICAL NOTES. 



good, there are, no doubt, a whole range of intermediate forms 

 between the variety and the type. I am convinced, that the 

 form has nothing to do with Pleurotœnium basiundatum 

 W. & G. S. West, to which it was originally referred by 

 Dr. Borge. 



Genus Triploceras Bail. 



Triploceras gracile Bail. 

 Bailey: in Smithson. Gontrib. IL 

 G.S.West: Algæ Yan Yean. 



The species was quite common, and the specimens observed 

 were of the more robust form of this variable microphyte. The 

 Desmid has a general tropical and subtropical occurrence, and 

 is very rarely observed in temperate districts. 



Genus Euastrum Ehrbg. 



Euastrmn denticulatum Gay. 



Gay: Note conj. d. m. de France. 

 Common. 

 Euastrum elegans forma medianum Nordst. 



Nordstedt: Freshw. Algae New Zealand. 



Rare. The forms observed agreed very well with the 

 drawings of Professor Nordstedt, and I do not hesitate to 

 identify the North Australian specimens with his forms. 



Euastrum, suhlohatum, var. hrevisinuosum Nordst. 



Nordstedt op. c. (Gosmarium sublobatum var. hrevisinuo- 

 sum). 

 Quite common. 



Genus Gosmarium Gorda. 



Gosmarium achondroides G. S. West. 

 G, S. West: Algæ Yan Yean. 



