564 DR. W. A. CUNNINGTON ON THE 



further records of distribution now ravailable which make our 

 knowledge more complete. It is safe to predict that future 

 investigation will add to the localities in Africa from which these 

 pai'asitic forms are known, even though it may not materially 

 increase the number of recognised species. 



Table of Distribution of Branchiura "^ . 



The outstanding feature revealed in the above list is that while 

 two species occur widely distributed in Africa, these are asso- 

 ciated in Nyasa with a single endemic form, but in Tanganyika 

 with no less than seven. Thus out of ten known African species, 

 nine are found in Tanganyika, which is therefore seen to possess 

 not only a larger number of characteristic species, but a much 

 richer Branchiuran fauna than the other great lakes with which 

 it may reasonably be compared. All the species enumerated are 

 confined to the African continent so far as is at present known, 

 Dolops ranarum is the only African representative of a genus 

 which is otherwise exclusively American. The genus Ghonopeltis 

 was established from a single female specimen from Lake Nyasa, 

 while Argulus alone has a distribution which is world-wide. 



OSTEACODA. 



It seems j)robable that the Ostracod-fauna of the gi-eat lakes is 

 less well represented in the collections hitherto obtained than is 

 the case with any of the other groups of Entomostraca. This 

 is due to the fact that nearly all fresh-water Ostracods are 

 bottom-living rather than planktonic forms, and require other 

 methods than surface tow-netting for their capture, while the 

 bulk of the material at present examined was collected by the 

 tow-net. This implies, of course, that many additional types 

 will probably be found when the lakes are more adequately 

 explored. Nevertheless, 22 species are on record for Tanganyika 

 (of which 20 are peculiar to that lake), and 17 and 7 respectively 

 for Nyasa and Victoria Nyanza. No Osti-acoda have so far been 

 recorded from Lakes Edward and Kivu. 



f For furtbev particulars, biblioG;rapby, etc., consult Cunnington (72). 



