Observations on the Genus Volvox in Africa. 467 



described from Khodesia (N'gamo) and the Bechuanaland Protectorate 

 (vleis and backwaters of the Linyanti River). 



F. Rousseletii G. S. West, previously fully known only from the 

 Ussangu Desert, has now been described from Egypt, from the Trans- 

 vaal (Rietfontein, Eliazer Pan, and Brakpan), from the Bechuanaland 

 Protectorate (Sedudu), and from the Eastern Province (Grahamstown). 

 Individuals from Rietfontein have been studied in the living condition, 

 and our knowledge of the species has been extended. A form from 

 the Kaokoveld (South- West Africa) has been noted which seems to 

 show certain different peculiarities. 



A new species, F. amboensis, from Ongka in Ovamboland, has also 

 been described. 



CONCLUSION. 



From the above it is obvious that the genus Volvox in its broadest 

 sense is widespread in Africa, and includes many distinct species and 

 forms. There is here an extensive field for study, and it remains for 

 further research to find whether some of these forms are not merely 

 local variations of a single very variable species, or whether they 

 remain true if grown under different conditions. 



The authors desire to express their gratitude to Professor F. E. 

 Fritsch, F.R.S., of the East London College, University of London, 

 for his very kind and valuable help and advice. 



The senior author is indebted to the Carnegie Corporation for the 

 Advancement of Research for a grant, made through the Research 

 Grant Board of the Union of South Africa, towards the expenses 

 incurred in this work. 



The microphotographs illustrating this paper have all been taken 

 by the junior author, with the exception of two of V . amboensis 

 kindly taken for us by Professor lyengar. 



