126 Mr. E. A. Smith on the Shells of the 



12. Bithynia Stardeyi, Smith, var. humerosa. 

 Bithynia Stanleyi, Smith, var. humerosa, Martens, /. e. p. 104. 

 Hob. South-west shore {M.) ; Lake Nyassa (Smith). 



11. Pelecypoda. 



13. Corhicula radiata, Pavreyss. 



Hob. River Nile ; also Lakes Albert, Tanganyika, and 

 Nyassa, Victoria Nyanza {Martens). 



I have already quoted this species from the Victoria 

 Nyanza (Ann. & Mag. Nat. Hist., Aug. 1890, p. 149). It 

 was obtained on the south shore of the lake both by Emin 

 Pasha and the late Bishop Hannington. Some of the speci- 

 mens are without rays, other examples, in addition to the 

 violet rays, exhibit others of a rich brown or reddish colour. 

 The epidermis is variable, being olive-green, greenish yellow, 

 or simply yellow. 



14. Limosina parasitica (Parreyss). 



Hah. First Cataract at Assouan on the Upper Nile 

 [Parreyss] . 



This species is considered by Clessin (Conch. -Cab. Monog. 

 Cycladeen, p. 247) synonymous with L.ferruginea^Y.YSiW&Q*. 

 On comparing specimens of these forms received from 

 Parreyss and Krauss they appear to differ somewhat both in 

 form and sculpture. L. 2^orositica is slightly longer and 

 narrower and the concentric lines are stronger and more 

 lamellar. The specimens obtained at the Victoria Nyanza 

 by Bishop Hannington are exactly similar to those from 

 Assouan. 



15. Um'o BaJceri, H. Adams. (PI. XXL fig. 11.) 

 Unio Bakeri, Martens, I. c. p. 104. 



Ilab. South-west shore (ilf.) ; Albert Nyanza [Sir Samuel 

 Baker and Emin Pasha). 



I have already (P. Z. S. 1888, p. 56) pointed out the 

 similarity between this and some of the following species 

 described by Bourguignat, and it seems very probable that 

 the shells referred to the present species by Dr. E. von 



* Besides South Africa I have already quoted this species from Mada- 

 gascar and Mauritius (P. Z. S. 1882, p. 388). 



