MOLLUSC A FROM THE SOUTHERN SUdAn. 265 



Martens, E. 0. von, 1897.-^Beschalte Weichtliiere. Thierwelt Deutsch-Ost-Afrika, vol. iv. 

 Neuville, H., and Anthony, R., 1906. — Liste MoUusques d'Abyssiuie. Bull. Mus. Hist. 



Nat.'Paris, xii. 319-321. 

 Pallary, p., 1909. — Catalog'ue Faune Malacol. Eg-ypte. Mem. Inst. Egypt. 

 PiiiSBRY, H. A.., 1904. — Manual of Concliology, vol. xvi. Limicolaria. 

 RocHEBRUNE, A. T. DE, and Germain, L., 1904.— Diagnoses MoUusques nouv. prov. de la 



Mission du Bourg. de Bozas. Bull. Mus. Hist. Nat. Paris, x. 141-144. 

 1904. — Mollusques recueillis par la Mission du Bourg. de Bozas. Mdm. Soc. 



Zool. France, vol. xvii. 

 Simpson, C. T,, 1900. — Synopsis of the Nai'des, or Pearly Freshwater Mussels. Proc. U. S. 



National Mus., Washington, vol. xxii. 



APPENDIX I. 



Description of Neio Species. By Hugh B. Preston, F.Z.S. 



Segmentina kanisaensis, Preston, sp. nov. (PI. 18. figs. 17-19.) 



Shell small, suborbicular, with concave spire, reddish brown ; whorls 4, 

 regularly increasing, the first three sunken, the last carinate below, marked 

 with oblique growth ridges, and sculptured with microscopic, wavy spiral 

 strige ; suture well impressed ; base of shell flat, slightly polished, sculptured 

 as above ; umbilicus rather shallow, wide, about one-fourth the diameter of 

 the shell ; columella margin very short and obliquely descending, diffused 

 above into a not very well defined parietal callus, which reaches to the 

 upper margin of the labrum ; labrum acute, receding below, projecting 

 above ; aperture bluntly sagittiform. 



Alt. 1, diam. maj. 4, diam. min. 3'25 mm. Aperture : alt. 0*75, 

 diam. 1 mm. 



Hah. Kanisa ; five specimens (Mrs. G. B. Longstaff). 



This would seem to be the shell cited as S. angusta, Jick.* by Pallary in 

 his paper entitled " Mollusques recueillis par le Dr. Innos Bey dans le 

 Haut Nil " t^ from which it differs chiefly in its less polished appearance, 

 flatter, more angular and broader form, more convex and less tightly coiled 

 earlier whorls, less concave spire, flatter base, and wider umbilicus. 



Streptaxis sudanica, Preston, sp. nov. (PL 18. figs. 15, 16.) 

 Shell perforate, ovately rectangular, whitish, thin, shining ; whorls 6, 

 the first very small, the second proportionately large, the third and fourth 

 regularly increasing, the fifth and sixth rapidly increasing and eccentric ; 

 the apical whorls smooth, polished, the remainder sculptured with oblique, 

 arcuate, rather closely set, transverse costulse, which become finer on the 



* Jickeli, 1874, 'Fauna Land- u. Siisswasser Moll. N.O.-Afrlkas,' pp. 220-221. 

 t Le Caire, Bull. Inst. Egypt., ser. iv. 1902, p. 90. 

 LINN. JOURN. — ZOOLOGY, VOL. XXXIL 23 



