260 MRS, JANE LONGSTAFF ON NON-MARINE 



conspecific, for there is no greater variation in form and colour than occurs 

 in a large series from one district^, such as I possess from Shabra Maut. 

 The nacre is generally deep pink; my entire specimen from Kosti is pale in 

 tone, and two shells M. Pallary has given me from Cairo and the Canal 

 Mahmoudich are respectively pearly white and white tinged with pink. 

 M. Pallary (Mem. Inst. Egypt, vol. vi. fasc. 1, 1909, pp. b'd, 8-4) has shown that 

 the forms regarded as distinct species under the names lepsii, Jickeli, eanaida, 

 Bourg., arcuata, Caill., and letourneuxi, Bourg., are merely stages in the 

 gj-owth of S. ruhens. I not only have examples from the White Nile 

 in these different stages, but also shells from Shabra Maut indicating them 

 clearl}' by the lines of growth. 



This species has previously been recorded from the White Nile, the Blue 

 Nile, the Bahr el-Ghazal, Abyssinia, Uganda, Lake Tchad, and its occurrence 

 in Egypt and also in West Africa has just been mentioned. 



The figure of S. loissmanni given by von Martens in ' Conch. Mittheil.^ 

 vol. iii. 1889, pp. 9, 10, is hardly distinguishable from an old example of 

 this species. It is from the Rivers Lubi and Lubihisch, tributaries of the 

 Congo, in S. lat. 5° 6'. 



Spatha innesi, Pallarij. 



Spatha innesi, Pallary, 1902, ' Moll, recueillis Iniies Bey,' Bull. Inst. Egypt, ser. iv. no. 3, 

 p. 97, pi. 2. lig. 2. 



Specimens were taken near Mogran, at Ad-Du\vcm, Tawila, Kosti, Gebel 

 Ahmad Agha, near Melut, at Kodok, and in Lake Shambc. They were most 

 numerous at Ad-Duwcm, where twelve examples were found in different 

 stages of growth. 



The holotype measures, long. 60, alt. 37, crass. 25 mm. My biggest shell 

 exceeds this, measuring, long. 72, alt. 42'5, crass. 28'5 mm. It is from 

 Ad-Duwem. The specimens vary in shape, some having the ventral sinuation 

 more pronounced, some are more elongated, while others have the test 

 considerably thicker. A small example from Melut is remarkaljly solid, 

 more oblong in form, with the posterior dorsal margui higher. 



This species bears some resemblance to the western form, S. chaizlana, 

 Rang, with specimens of which I have compared it, but I fully agree with 

 M. Pallary in considering it distinct. 



The exact locality of the holotype is not given, but .since Dr. Innes Bey 

 kindly gave me an example from Kaka, it may also be from the same 

 habitat. 



Spatha wahlbergi, Krauss. 



Iridina tvcchlberffi, Krauss, 1848, Siidafrik. MolP p. 19, pi. 2. fig. 1. 

 Spatha hartmanni, von Martens, 1866, Malak. Blatt. vol. xiii. p. 10. 



Four entire specimens were taken near Mogran, and a single valve at 



