492 Annals of the South African Museum. 



Genus EUDORINELLA Lemmeemann. 



1. Eudorinella wallichii (Turner), Lemmerraami, Ber. Deutsch. 

 Bot. Ores., xviii, 1900, p. 307. (Syn. : Eudorina ? wallichii, Turner, 

 K. Sv. Vet.-Ak. Handl., xxv, 1892, p. 155, Tab. XXT, fig. 10.) 

 (Figs. 1,2.) 



Samples 30a, 31, 33. 



The typical mature colony is composed of two series, each of four 

 cells, enclosed within a spherical mass of transparent mucilage ; the 

 two series of cells lie in parallel planes, the cells of the one series 

 alternating with those of the other (cf. Eig. 1 and Fig. 2, d). As a 

 result, in a lateral vieAV of the colony, one usually sees two cells of the 

 one tier and three of the other (<f. Fig. 2, a). The cells of the mature 

 •colony are spherical, with a diameter of 8-9//.; they have a well- 



Fig. 1.— Diagram to show the disposition of the cells in a typical mature colony 

 of Eudorinella wallichii (Turner), Lemmernmnn, very much magnified. 



marked pyrenoicl and are provided with a slight papilla at the anterior 

 end, from which the cilia, doubtless arise (Fig. 2, /). Cilia were not 

 mentioned in the original description by Turner (he. cit.), based on 

 Wallich's manuscript, but have been subsequently recorded by Lemmer- 

 mann (lor. cit.) ; it is not quite clear, however, on what material his 

 conclusions are based. 1 have been unable to observe cilia in the 

 South African specimens, but there is no reason to doubt their 

 presence. Each cell is surrounded by a distinct but delicate membrane 

 of its own. 



Frequent specimens showing formation of daughter-colonies were 

 encountered. Prior to division the mucilage-envelope widens out 

 somewhat and, at this stage, its limits are often more sharply marked 

 than at any other time. It appears that in some cases the two tiers 

 of cells separate from one another before or during division, but often 

 the two tiers are readily recognisable up to the time of the formation 

 of mature daughter-colonies (cf. Fig. 2, b and e) ; as will be seen from 

 the figures, one or more cells of the mother-colony not uncommonly 

 fail to divide. T have not been able to observe all the stages in the 

 formation of daughter-colonies, but it appears as though here, as in 



