FAUNA OF THE AFRICAN LAKES. 



Table of Dist^'ibution of Macrura f. 



555 



Name of Species. 



Tangan 

 yika. Nj'anza. 



Victoria xt Albert 



Nyasa. 



Edward Other parts ot 

 Nyaiiza. Nyaiiza. the world. 



Family PALSMONiDiE. 



Palaamon moorei 



E 

 Family Atyid^. 

 Caridina nilotica 



var. giacilipes 



Limiiocaridina retiarius Gen. E 



„ parvula E 



., tangauyika3 ... E 



„ similis E 



„ latipes E 



„ socius E 



„ spinipes E 



Limiiocaridella alberti 



Caridella cuiiiiingtoni Gen. E 



,, minuta E 



Atyella bvevirostris Gen. E 



longirostris E 



p* 



Asia, Australia. 



Gen. E 



The adjoining table show.s at a glance the most striking 

 feature of distribution, namely that while Caridina nilotica var. 

 (jracilipes + occurs in nearly all the big lakes of Africa, it is not 

 found in Tanganyika, but is replaced there by 12 endemic species 

 belonging for the most part to endemic genera. Lake Albert 

 also contains an interesting endemic form (obtained by the 

 German Central Africa Expedition and described by Lenz 

 (109, p. 132) and Bouvier (52, p. 575)) in addition to the above- 

 mentioned widely distributed Caridina, while Kivu is the only 

 lake of those at present under review in which prawns have not 

 hitherto been observed. 



The first species of prawn ever taken in the African lakes was 



t A detailed account of the Macrura of the Third Tanganyika Expedition is given 

 by Caiman (61), and forms the principal source of information on tliis grouji. 



* The species of prawn collected by Schubotz at Kassenje on Lake Albert was 

 described by Lenz (109, p. 130) as Caridina Imigirostris Milne-Edwards. It is, 

 however, commonly agreed that longirostris is identical with the earlier nilotica. 

 so that, apart from the varietal name, this is the same form that occurs so widely 

 distributed in Africa. Since the type described as Caridina nilotica var. gracilipes 

 is certainly rather variable, it seems probable that the Lake Albert specimens are not 

 sufficiently distinct to bo recorded under a different name, and this is the view which 

 I have taken in compiling the table of distribution above. For a discussion of these 

 questions of synonymy consult the paper of Caiman (61, p. 189 et seq.) and the 

 subsequent paper of de Man (110), which arrives at somewhat different conclusions. 



I [ adopt the varietal identifications of Hilgendorf (100), Caiman (61), and Lenz 

 (109), but it is only right to point out that de Man (llO) takes a different view. 

 He appears to consider that the form occurring in Lake Victoria is to be referred to 

 the typical Caridina nilotica itself, and the form from Nyasa to his newly estab- 

 lished variety natal ensis . The type Caridina nilotica var. gracilipes he records 

 only from the islands of Celebes and Salayer in the Malay Archipelago. 



37* 



