Observations on the Genus Volvox in Africa. 471 



PLATE XXII. 



FIG. 



A. V. Rousseletii, male colony from Sedudu. x 83. 



B-E. V. Rousseletii f. kaokoensis : B, asexual ( x 50), C, mixed ( x 50), D, male 

 ( x 63), E, female colonies ( x 35). 



PLATE XXIII. 



V. Rousseletii f. nov. kaokoensis. 



A. Colony with ripe oospores (stained Delafield's haematoxylin). x 55. 



B, C. Oospores. x 800. 



D. Cells from a male colony with a developing sperm globoid (bowl stage). x 800. 



E, F. Sperm globoid in surface view and side view. x 800. 



PLATE XXIV. 

 A-C. V ' . amboensis sp. nov. 



A, B. Female colonies : A, with anterior pole ; B, with posterior pole tipped 

 towards observer. x 40. (Microphotographs by Professor lyengar.) A, 

 1100 xlSOO//. 



C. Mature oospore. x 800. 



D. A typical Volvox vlei on the Cape Flats (Ottery Road, Wynberg). Oxalis 



natans in flower on the water. 



