Volvox and Associated Algae from Kimberley. 499 



Coen. infant, num. . . 4-19 



Glob, sperm, num. . . ?-800 



Oospor. num. . . . ?-655 



Coen. juvenil. . . . 215-322 p x 258-366 p 



Coen. juvenil. embryon. . 129-215 /z x 139-240 /A 



Coen. juvenil. cell. num. . ca. 330-418 



Found in all stages in Pool I ; asexual only in Pools II and III. 



This form combines characteristics of various forms of Volvox 

 Rousseletii and its allies the very large number of sperm globoids 

 (Plate XXXV, A, B) suggests the material from Ussangu (West, 

 1918, p. 2), while in the unusually high number of oospores (Plate 

 XXXV, D, E), often several hundreds, it resembles Volvox amboensis 

 (Kich and Pocock, loc. cit., p. 462); on the other hand, the sexual 

 colonies, although on the whole larger than usual, do not reach 

 anything like the size attained in the Ovamboland material, and very 

 large asexual colonies are on the whole rare and slightly below the 

 maximum size observed in the Bietfontein cultures. 



It is typically dioecious, the male colonies (Plate XXXV, A, B, D) 

 being better developed and more numerous than in any other form 

 as yet examined ; but an occasional sperm-globoid in otherwise female 

 colonies is not unusual, this again suggesting a resemblance to 

 V. amboensis. The oospores (Plate XXXV, F) are usually slightly 

 smaller than in the Rietfontein material, with shorter spines, and are 

 intermediate between that form and the form from the Kaokoveld 

 (forma kaokoensis, Bich and Pocock, p. 460). 



The asexual colonies are often markedly egg-shaped, particularly 

 in the purely asexual material from Pools II and III which is in- 

 cluded here, although sexual colonies are lacking. In the more egg- 

 shaped coenobia the embryo colonies are nearer the posterior pole 

 than usual, even the most anterior being definitely posterior to the 

 equator. In purely asexual material the number of embryo colonies 

 is high, usually over eight, as many as 19 having been counted, while 

 12 to 14 are common. During the sexual phases the asexual colonies 

 are smaller and contain fewer daughters, usually under eight (Plate 

 XXXIV, A, B). 



The Juvenile form (Plate XXXIV, G, E) was collected in great 

 numbers on one occasion, and is similar to that of V. Rousseletii 

 and of V. capensis, but is slightly larger, composed of rather more 

 cells, and usually produces two or three embryos (Plate XXXIV, C), 

 while as many as five were seen. 



