108 Beport of the Bilharzia Mission in Egypt, 1915 



Pallary has specimens from Alexandria, Cairo, and Suez. He 

 states that it is distributed alonf/ tlie Nile and its tributaries. 



'i 



Fig. IQ.— Valvata nilotica. (x 2.) 



Hydrobiid^. 

 Bythinia (Gabbia) sennaarica, Parreyss, 1853. 

 About eighteen specimens in all occurred amongst the material 

 collected from Marg. A few examples were found in the ponds of 



Fig. 79. — Bythinia (Gabbia) sennaarica. (x 2). 



the Zoological Gardens, Giza, and a couple were dredged from the 

 ferry over the Sweet Water Canal at Ismailia. 



Pallary does not give specific localities, but says that it is dis- 

 tributed along the whole Nile. Mrs. Longstaff collected specimens 

 from " ponds near the Pyramids of Gizeh " and at several places on 

 the White Nile. 



Hydrobia stagnalis, Linnaeus. 



We failed to find this form. It is reported by Pallary to occur 

 in Lake Mariout, Alexandria, and at Rosetta. Smith mentions its 



4 I 



Fig. 80.— Hydrobia stagnalis, Bgt. (x 2.) 



presence in Lake Qurun, Fayiim and Jickeli lists it for North-East 

 Africa. 



Melaniid^. 



Melania tuberculata, Miille)-, 1774. 



This is a very common form lying usually on the surface of the 



umd at the bottom of canals, ponds and birkets. It varies greatly 



in size. The largest forms collected were those obtained from the 



ponds in the Zoological Gardens, 



