39:; 



REMARKS ON TWO SPECIES OF AFRICAN VOLVOX. 



By Charles F. Eousselet, F.R.M.S. 

 (Read October 21th, 1914.) 



The slides of two species of African Volvox which I am 

 exhibiting to-night have a history of unusual interest. 



It will be remembered that at the meeting of this Club on 

 October 25th, 1910, a paper was read by Prof. G. S. West of 

 Birmingham University, in which two new species of Volvox 

 from Africa were described. 



One of these, Volvox africames, of small size and oblong in 

 shape, was found in a Plancton collection made in July 1907 

 by Mr. R. T. Leiper, of the Egyptian Government Survey, near 

 the northern shores of the Albert Nyanza. I received a very 

 small quantity of this collection for the purpose of determining 

 the Rotifera it contained, and found these pretty oval colonies of 

 Yolvox, as did also Prof. West, who had received a similar 

 sample, in order to name the various fresh-water algae 

 contained therein. 



The other species is of very much larger size (as much as 

 l/20th inch in diam.), of spherical shape and densely crowded with 

 cells on its surface (estimated at 50,000 cells in one of the larger 

 Colonies), was found by myself on the occasion of the visit of the 

 British Association to South Africa in September 1905 at 

 Gwaai Station in Rhodesia, about half-way between Bulawayo 

 and the Victoria Falls of the Zambesi ; the train stopped for 

 half an hour at this station by the side of a shallow pool formed 

 by the Gwaai River, and as usual I jumped out of the train with 

 my collecting- net and bottle and secured a dip from the pool. 

 As the train went on I examined the contents of my bottle, and 

 besides various Rotifera I noticed some large colonies of Volvox. 

 The whole collection was put up in formalin, and eventually the 

 specimens of Volvox were handed over to Prof. West for 

 description, which was done in our Journal in November 1910.* 



Of both these African Species of Volvox vegetative colonies 

 only had been found, and Prof. West expressed his regret that 

 the sexual colonies in various stages were not represented, so 

 that his description was necessarily incomplete. 



This closed the first stage of the story. 



In May 1912 Dr. A. W. Jakubski published in the Zoologischer 

 Anzeiger a paper on Rotifera collected by him in the Ussangu 

 Desert in German East Africa, in which several new species of 

 Distyla were figured and described. At that time Mr. James 

 Murray was writing papers on the Rotifera of Australasia and 

 South America and in particular was studying the family of the 



* Journ. Q.M.C., Ser. 2, Vol. XL, p. 99-104. 



