498 Annals of the South African Museum. 



are sufficient to show that there are several differences in detail, and 

 the whole process of inversion is complicated by the large size of the 

 gonidia. 



The two new records for F. africanus, i.e. from the Linyanti River 

 (Rich and Pocock, loc. cit., p. 441) and the present one from Kimberley, 

 are interesting, extending its range in Africa considerably. It is 

 evidently widespread in the warmer regions of the world, having now 

 been recorded from Albert Nyanza, Tanganyika, Rhodesia, and 

 Kimberley in Africa, the Philippines, and S. India (lyengar, 1933). 

 So far, it seems to be nowhere abundant. Possibly, like V. gigas, 

 it is slow in developing and undergoes a prolonged asexual phase 

 followed by a relatively brief period of sexual activity. It will be 

 especially interesting if it proves possible to study it in life, since 

 so far, apparently, all descriptions, even Shaw's, have been made 

 from preserved material only. 



The Kimberley material is outstanding both from its larger size 

 and the very regular development of four pairs of embryos ; in the 

 earlier collectings two and four have been the usual numbers of 

 embryos, with six occasionally, although Shaw, 1923, p. 197, found 

 in the Manila material a small proportion of colonies containing 

 eight. 



Section Eu-VoLVOX Printz. 

 3. Volvox Rousseletii G. S. West. 



Forma griquaensis f. nov. 

 (Plates XXXIV to XXXV, A to E.) 



Forma coenobiis sexualibus majoribus quam in forma typica, 

 antheridiis oosporisque permultis. 



Coen. asex. . . . 710-1809^x904-1900^ 



Coen. masc. . 471-1443 p. x 559-1550 p. 



Coen. fern. . . . 600-1464 /z x 644-1636 p, 



Coen. infant, . . ? -494 ^ x ? -517 ^ 



Cell. veg. . . . 8-13 ^ 



Pplast. veg. . . . 4-6 p, 



Glob, sperm. . . 35-41 ^ x 18-22 ^ 



Oospor. .... 40-53 JJL 



Oospor. sine sp. . . . 35-40 JJL 



Spin. long. . . . 5-9 JJL 



Cell. num. ad ca. 43,000 



