Entomostroca from Egypt and the Soudan. 29 



The occurrence of this species in the Birket el Kurun 

 seems further to justify the specific name, as it appears to' be 

 a species characteristic of water of a high salinity. 



(14) Ilyocryptus sordidus, Lievin. 



Four rather immature specimens occurred in a collection 

 made in a canal at Lecht which runs from the Nile near 

 El-Wasta northwards as far as the barrage below Cairo. 



A much mutilated specimen of a species of Ilyocryptus 

 ■was found in the Blue Nile, but I am unable to identify it 

 with certainty. In the form of the postabdomen it agrees 

 most closely with /. longiremis, Sars. 



(15) Camptocercus australis, Sars. 



Found in the sweet-water canal at Port Said and in pools 

 in the Zoological Gardens at Cairo. Hitherto the species 

 has been recorded only from the Oriental and Neotropical 

 regions. 



(16) Alona affinis, Leydig. 



Two rather decayed specimens were found in the Nile 

 near Luxor. 



I cannot agree with Keilhack (1909) in regarding this 

 species as a variety only of Alona quadrangidaris. The two 

 species differ, in my experience, not only in habit, but iu 

 quite constant structural features. 



(17) Alona rectangula, Sars. (PI. II. fig. 5.) 



In pools by the road to the Pyramids and at Dahchour. 

 Ekman describes specimens from Gizeh and the White Nile 

 which he refers to Alona bukobensis, "\Yeltner, but it seems 

 to me that Daday (1907) is right in considering A. buko- 

 bensis as a synonym of A. rectangula. The form of the 

 postabdomen in both is extremely variable and the variations 

 in form and arrangement of the denticles evidently overlap 

 each other. My own specimens are very few and do not 

 show much variation; the postabdomen closely resembles 

 that of the typical European form of the species (fig, 5). 



(18) Leydigia quadrangularis , Leydig. 



Two specimens only were found in a pool in the Zoolo- 

 gical Gardens at Cairo. 



