107 



OOCYSTIS AND EREMOSPH.ERA. ' 



Bv G. I. Playfair, Science Research Scholar of the Uni- 

 versity OF Sydney. 



(Plates vii.-ix., and 28 Text-figs.) 



During the past eight years, 1907-1915, a considerable niunber 

 of gatherings of freshwater algfe, from Sydney and suburbs, and 

 from the neighbourhood of Lismore, on the Richmond, have 

 accumulated in my hands. In going through these samples on 

 various occasions, I noted the presence of forms of Oocystis and 

 Eremosphcera in such numbers and variety, that it seemed to me 

 worth while to give a particular account of the two genera, as 

 found in this country. To this end, I have made a thorough 

 examination of my gatherings, to the number of 256, in 52 of 

 which forms of Oocystis and Eremosphcera occur more or less 

 plentifully. It is somewhat unfortunate that I had to work from 

 preserved material, as, for this reason, the disposition of the cell- 

 contents could not, in many cases, be recorded with certainty. 

 This, however, may be discounted by the fact, that the chloro- 

 plasts are of the same character in almost all forms of Oocystis 

 and Eremosphcera, and, for the rest, I had the advantage of a 

 fair number of notes and figures made from the same material 

 when it was just freshly gathered. 



Samples. — The localities from which each form is reported are 

 mentioned in the notes on the various species; the following list 

 gives all the samples referred to in this paper, classified accord- 

 ing to the habitat from which they were derived. The numbers 

 refer to gatherings preserved in formalin, in the National Her- 

 barium, Sydney. 



Nos.49, 56, 59, 67, 79, 104, 105, 107, 118, 119, 124, 135, 138, 

 139, 140, 148, 149, 159, 163, 164, 171, 174, 185, 240, from 



