Iti88.] FROM THE ALBERT NYANZA. 53 



liris spiralibus 2-3 circa partem inferiorem instructi, sutura sub- 

 profunda, obliqua sejuncti ; ulthnus circa medium et basim liris 

 paucis cinctus ; apertura pyriformis, intus ccerulescens ; peris- 

 toma tenue, marginihus callo tenui junciis. Longit. anfractuum 

 quinque 26, diam. 9| millim. ; apertura 9^ longa, 5g lata. 



Fig. 1. 



Melania liricincta. 



On removing the thickish epidermis the shell has a dirty whitish 

 appearance. The spiral ridges are usually rather strong and vary 

 in number to some extent. Two specimens have four round the 

 nniddle part of the body-whorl and four at the base, the two sets 

 being separated by a smooth blank space. Two or three of the 

 upper series usually revolve up the spire upon the lower portion of 

 the upper whorls. 



M. victoria, Dohrn, from the Victoria Falls, Zambesi River, is an 

 allied form. 



3. Ampullaria wernei. 



Amp. wernei, Philippi, Conch.-Cab. ed. 2, p. 19, pi. 5. f. 4, 

 pi. 17. f. 2 ; Martens, Novit. Conch, vol. iv. p. 22, pi. 1 14. figs. 1-5. 



Lanistes, sp.?, H. Adams, Proc. Zool. Soc. 1866, p. 376. 



Hab. White Nile {Philippi) ; Gazelle River (». Martens) ; Albert 

 Nyanza {Baker). 



The two young shells referred to the genus Lanistes by Adams 

 appear to be the early stages of this species. 



4. Paludina unicolor, var. 



There are in the British Museum twelve specimens from the 

 Albert Nyanza, received from the late General Gordon and Sir 

 Samuel Baker, which are precisely similar to those just obtained from 

 Emin Pasha. They may be regarded as a well-marked variety of 

 P. unicolor, Oliver, although differing considerably in outline from the 

 typical form . They appear to be smaller and narrower ; the whorls are 

 more rounded and without any indication of angulation at the upper 

 parts, and exhibit more spiral striation. The colour seems to vary 

 considerably : some are entirely of a pale rosy tint ; others are nearly 

 white ; one or two specimens belonging to Mr. "Waller are of a pur- 

 plish-brown colour, a few are olive-yellow, and the majority exhibit 

 a more or less distinct pale zone at the periphery, which sometimes 

 has a dark baud below it. 



