244 MRS. JANE LONGSTAFF ON NON-MARINE 



IsiDORA TRUNCATA (Fer.), Bourg. 



PMjsa truncata, Ferussac, Audouin, 18:^6, 'Explic. Sommaire des Planches Moll. Egypte 

 et de la Syrie par Savigny,' vol. i. pi. 4, p. 33. Savigny, ' Descr. de TEgypte,' 1812, 

 pi. 2. fig. 27. 



Physa tnmcata, Bourguignat, 1856, 'Amen. Malac' vol. i. p. 176, pi. 21. figs. 5-7. 



Fonr specimens were found at Hillet Abbas and two at Gebel En on 

 water-plants at the edo-e of the river. Tbev were previously mistaken for 

 1. sericina, Jickeli (' Butterfly Hunting in Many Lands/ by G. B. Longstaff, 

 1912, p. 124), which had been recorded from the district by Herr Hagg. 

 They have, however, a much flatter spire and a longer body-whorl. 



The laro-est example is from Hillet Abbiis; it measures, alt. 9'25, diam. 

 6 mm. The smallest, from Gebel En, has an alt. of G mm. 



Jickeli unites I. truncata with I. contorta, Mich., considering it a young 

 stage of that species, but this can hardly be the case for they differ in form, 

 and my biggest shell exceeds in size the dimension he quotes for i. contorta. 

 It may more probably be a variety of /. broccJui, Ehrb., to which it bears a 

 greater resemblance, as they both have a narrower aperture than /. contorta. 



Bourguignat states that it is widely spread in Syria and Egypt and that it 

 occurs both living and fossil in Algeria. Germain records it from Lake 

 Tchad. 



ISIDORA CONTORTA, Mich. 



Physa contorta, Michaud, 1829, Bull. See. Linn. Bordeaux, vol, iii. p. 268, figs. 15, 16. 



Only one specimen was found, on Masrau Island, but many were taken in 

 Lake Shambe, most of which were immature. Three or four shells have 

 strong raised threads running down the whorls along the course of the lines 

 of growth. 



This species was previously found in the White Nile by Prof. Schweinfurth 

 and recorded by von Martens. It has a very wide range, being reported 

 from Southern Europe, North, West, and South Africa, Abyssinia, and the 

 Euphrates. 



IsiDORA DYBOWSKii, Fischer, var. 



Bullinus dybotvskii, Fisclier, 1891, ' Moil. Miss. Dybowsky,' p. 365, pi. 3. figs. 4, 4 a. 



A single example was taken alive at Kaka. It appeared to me like the 

 shell figured by M. Pallary in 'Cat. Faune Malac. Egypte/ pi. 3. fig. 34, as 

 a variety of Isidora dyhowsUi. I therefore sent it to him, and he confirmed 

 my identification and stated that it was not quite mature. This is a new 

 record of the species in the White Nile. 



It has previously been found in Lower Egypt, and also sub-fossil in the 

 Algerian Sahara at El Golea (Pallary'). 



