FAUNA OF THE AFRICAN LAKES. 



545 



Name of Species. 



Taugan- 

 yika. 



Family Limnjeid^. 

 Limn*a natalensis P 



„ nyansse 



„ undussumiB 



Isidora coulboisi E 



,, foi'skrtli 



„ iiyassaiia 



„ raiidabeli E 



„ stvigosa 



„ succiiieoides 



,, ti'ansversalis 



,, trigoiia 



Pbysopsis africaua 



„ ovoidea 



„ tangauyicae E 



Family PLANORBiDiE. 



Plaiiorbis adowensis P 



„ alexandriiia P 



„ apertus 



„ bridouxiaiia E 



„ choaiiompbalus ... 



„' crawfovdi 



„ gibbonsi 



„ lamyi E 



„ lavigeriauus E 



„ monceti E 



„ staiileyi 



„ sudaiiicus P 



„ victoria; 



Family Ancylid^. 



Aucylus stuhlmanni 



„ tangauyicensis E 



Victoria 

 Nyaiiza. 



Nvasa. 



Albert P]d\vard 



Kivu. 



Other parts of 



K. Nile. 



A list such as this, with 133 species, requires a somewhat 

 detailed analysis to bring out the points of most interest and 

 importance, although, indeed, the tabular form reveals the excep- 

 tional nature of the Gasteropod fauna of Tanganyika. In the 

 first place it will be noticed that no less than 84 species are 

 recorded from Tanganyika, which is clearly an exceptional number. 

 That this is so, is shown by a. comparison with the known fauna 

 of the two lakes which come neai-est in size, for Victoria Nyanza 

 can muster but 28 forms and Nyasa only 24. Thus Tanganyika 

 contains three times as many Gasteropods as Lake Victoria and 

 u:iore than three times as many as Nyasa. 



Secondly, be it observed, that of the 84 Tanganyika species, no 

 fewer than 76 are endemic, while correspondingly onl}^ 11 out of 

 28 are peculiar to Victoria Kyauza and 10 out of 24 to Nyasa. 



