the Victoria Nyauza or Lake Oukerewe. 381 



The British Museum has recently obtained a small collec- 

 tion made by the Rev. E. Cyril Gordon at both the north 

 and south shores of the lake. This series, consisting of 

 eleven species, contains nine which are new to the Museum, 

 four being also new to science. The finest species, belonging 

 to the genus AnijJuUaria, hitherto unknown from the lake, is 

 the largest of that group as yet recorded from the African 

 continent, and the Sphceriuni represents a genus which, 

 besides being sparingly represented in Africa, is also new to 

 the lake. 



In addition to the above species Mr. Gordon also obtained 

 the yEtheria elliptica from the Nile at the Ripon Falls. 

 This species was found at the soutiiern part of Lake Victoria 

 by the late Bishop Hannington. 



I. Additional Species described hy Dr. E. von Martens. 



1. Limnoia nyansce^ Martens. 



Limncea mjanste, Martens, SB. Gesell. iiat. Freund. Berlin, 1892, no. 2, 

 p. 16. 



llah. West shore at Bukoba and Towalio. 



2. Physa trigona^ Martens. 



Physa ti'iyona, Martens, /. c. p. 17. 



Ihib. Bukome in South-west Creek {Martens) ; North end 

 [dor don). 



3. Viviparns phthinotropis^ Martens. 



Vivipctrus phthmotro2))s, Martens, /. c. p. 17. 



llah. Njaraagolso, south-west part of lake. 

 This species may be the same as my V. victorice. 



4. Viviparus trochlearis, Martens. 

 Vivipanis trochleans, Martens, /. c. p. 18. 



Hah. Sirwa Island. 



5. Viviparus costulatus^ Martens. 

 Viciparus costulatus, jNIartens, /. c. p. 18. 



Hub. Kassarasi Island. 



