10 Richard Httgg. 



Literature: 



1) PlanorUs Uissyi Potiez et Michaud 108 (I, p. 208, pi. 21, f. 4—6), 

 117 (pi. 2, f. 26), 93 (p. 39), 50 (p. 11), 54 (p. 213, T. VII, f. 20), 47 (p. 329), 

 87 (p. 115). 2) Planorbis orientalis Olivier 2 (p. 166). 3) Planorbis alexandrima 

 Both, non Ehbenbbbg 115 (p. 2, pi. 2, f. 8). 



11. Isidora sericina Jickeli. 



Alt. 5 mm. Lett. 3,5 mm. 



Hob. Gebel Ahmed Agha. On water plants in back-water. 

 20 . 3 . 1901. One living specimen. 



Geographical distribution: 

 Countries northeast of Abyssinia: in the province of Hamas- 

 zen at Mekerka on Toquor (Jickeli [50]). 



This species is consequently new for the White Nile. 

 Literature: 



50 (p. 43), 54 (p. 194, T. 3, f. 2, T. 7, f. 11). 



12. Isidora forskali Ehrenberg. 



Alt. 3,7 mm. Lat. 2.9 mm. 



Hab. Gebel Ahmed Agha. On water-plants in back-water. 

 Two living specimens. 



Geographical distrib utio n: 



Loiver Egypt (Ehrenberg and Hemprich [32], Heuglin and 

 Steudner ace. to v. Martens [71], Jickeli [50]). The Nile (Pru- 

 ner ace. to Roth [116]). Countries northeast of Abyssinia (Schiller 

 ace. to v. Martens [74], Beccari and Issel ace. to Morelet [94], 

 Jickeli [50]). Abyssinia: southern part (Heuglin and Steudner 

 ace. to v. Martens [72]). Arabia: Aden (Issel ace. to Paladilhe 

 [100]). Zanzibar (Sthulmann ace. to v. Martens [87]). Baga- 

 moyo (Stuhlmann ace. to v. Martens [87]). Natal (Wahlberg 

 ace. to Krauss [59]). Benguella (Tams ace. to Dunker [31]). 

 Angola (Wellwitsch ace. to Morelet [93]). Cape Verde Islands 

 (Dohrn [30]). 



This species is consequently new for the White Nile. 



Literature: 



1) Isidora forskali Eiikenbero- 32, 9 (I, p. 174), 71 (p. 6), 72 (p. 100), 75 

 (p. 213), 93 (p. 39, 40), 94 (p. 208), 50 (p. 11, 22, 36, 50, 55), 87 (p. 115). 

 2) Physa lamellosa Roth 116 (p. 49, pi. 2, f. 14—15), 9 (I, p. 174), 71 (p. 6), 





