( 473 ) 



4. Volvox and Associated Algae from Kimberley. By M. A. POCOCK, 

 Ph.D., F.L.S. With Field Notes by J. H. POWER, F.Z.S., 

 F.R.S.S. Africa. 



(With Plates XXV-XXXVII and 7 Text-figures.) 



CONTENTS. 



PAGE 



Part I. Introductory .... . 473 



Part II. Description of the Species .... . 479 



Eudorina elegans Ehrenb. ... . 479 



Volvox gigas sp. nov. ... . 480 



Volvox africanus G. S. West ....... 492 



Volvox Rousseletii G. S. West 



forma griquaensis f . nov. ...... 498 



Sphaerocystis Poweri sp. nov. ...... 501 



KirchnerieUa africana sp. nov. ...... 506 



Part III. Field Observations and Records ...... 509 



Summary ....... . 513 



Discussion and Conclusion . . . . . . . . .514 



Bibliography ........ . . 515 



Description of Plates ... .517 



PART I. INTRODUCTORY. 



TOWARDS the end of the year 1931, while examining pools in the 

 neighbourhood of Kimberley for fresh-water Crustacea, Mr. J. H. 

 Power found Volvox in abundance in a small quarry pool. The 

 material collected was sent, with the Crustacea, to the South African 

 Museum and handed to the writer for investigation. The Volvox 

 proved to be a large form, apparently of the type of Volvox Rousseletii 

 West, but as it was purely asexual an exact determination could not 

 be made. A request for further material, however, resulted in a 

 second collection made early in December, in which there was abund- 

 ant sexual material of all ages, the sexual colonies if anything out- 

 numbering the asexual. The provisional diagnosis made from the 

 first material was in the main confirmed ; but although obviously 

 very closely allied to the material from Rietfontein (Rich and Pocock, 

 1932, p. 455), which may be regarded as typical, it yet differed from 

 it in some details. It was thought, therefore, that it might be 

 VOL. xvi, PART 3. 31 



