FAUNA OF THE AFRICAN LAKES. 559 



the exceptional opportunities they are known to possess for 

 obtaining worhl-wide distriliution, cannot afford evidence of the 

 same value as the higher forms. When — as is particularly 

 the case among the Cladocera — even specific forms of cosmo- 

 politan range reappear in the great lakes, it becomes clear that 

 the precise geographical distribution of such species is a matter 

 of no great significance. At the same time, the possibility is not 

 excluded that the lakes may difter in their suitability to harbour 

 certain types, while it is highly probable that new types can and 

 will develope in some cases, constituting species or even genera 

 of an endemic nature. Thus a study of the distribution of these 

 forms in tlie lakes of Central Africa is nevertheless not devoid of 

 interest, and may indeed furnish testimony of some importance, 



EUCOPEPODA. 



The Eiicopepoda so far observed in the lakes with which this 

 paper is concerned reach the not inconsiderable total of 54 

 species. Of these, more than half (31) have been found in 

 Tanganyika, to which lake a Lu-ge proportion exclusively belong. 

 There is every reason to believe tha,t further investigation will 

 bring- to liaht additional forms, particularly from Victoria 

 Nyanza and the smaller lakes, which, in this respect, have 

 received less attention than Tanganyika an^l Nyasa. 



Table of Distribution of Eucopepoda t. 



TVT Albert Edward t-- Other parts of 



^yas"- Nyanza. Nya.iza. ^^''"'- the world. 



E 



P ... ... ... E.Africa. 



E 



P .. ... ... E.Africa. 



P§ ... ... ... Asia, S. America. 



P§ ... ... ... S. America, New Guinea. 



P ... ... ... Asia, New Guinea. 



t Detailed nifovmation concerning a large proportion of these species is given by 

 Sars (151). The other sources of most importance are Daday (76, p. 106) and 

 Mrazek (139). For the Lernaidie consult Cunnington (73). 



X I follow Sars (151, p. 34) in assuming that this form, which is one of the 

 commonest and most characteristic species of Lake Victoria, is not identical with 

 the Egyptian D. galehi Barrois, as supposed by MrAzek and Daday. 



§ Not actually recorded from the lake itself, but from within its drainage area. 



