MOLLUSCA FROM THE SOUTHEEN SUDAN. 245 



IsiDORA (Pyrgophysa) FORSKALI, Elirh, 

 Isidomforskali, Ehrenberg, 1831, ' Symb. Phys.' No. 3, p. 174. 



One specimen was found alive in Lake Shainbe. It is of medium size, 

 consisting of four and a half whorls which measure^ alt. 6*75 mm. 



The species is reported from North, East, West, South, and Central Africa, 

 Aden, Mauritius, and the Cape Verde Islands. 



Suborder STYLOMMATAPHORA. 



Family Testacellid^. 

 Streptostele ? sp. 

 One dead specimen at Sheik Tombe. 



Streptaxis ? sp. 



Four dead shells at Sheik Tombe too imperfect to identify. 



Streptaxis sudanica, sp. nov. 



Three specimens at Sheik Tombe. A description by Mr. Hugh Preston 

 will be found in Appendix I., p. 265. 



Family L i M A c i D ^. 

 Helicarion ? sp. 

 One dead specimen at Sheik Tombe. 



Martensia sp. 



Two dead immature shells at Rejaf Wooding Station. Four in similar 

 condition, probably the same species, found among scrub at Rejaf. 



Family Stenogyrid^. 

 Genus LiMicoLARiA, Schumacher. 



LiMICOLARIA FLAMMATA^ Caill. 



Cochlogena flammata, Cailliaud, 1823, 'Voyage a Meroe/ vol. ii. pi. 60. figs. 4, 5, vol. iv. 

 1827, p. 265. 



I obtained about eighty specimens of this species. They show a consider- 

 able amount of variation, and at localities where a series was taken shells of 

 the stouter typical form were associated with others varying in their degree 

 of slenderness. 



