G4 MOKMYBIDJE. 



dark, their eyes shine very remarkably, sometimes white, sometimes gleaming red. 

 They soon learn to feed by daylight, and it is an interesting sight to see them 

 searching the bottom of the tank, examining every stone and cavity with their long- 

 snouts, for the pieces of chopped earth-worms which are daily put in for them to feed 

 on. Like many other species of fish they fight a great deal among themselves, and 

 several individuals which died from time to time during 1903, it is believed, had been 

 killed by their comrades ; but latterly these fights have been less frequent. Like the 

 Gnathonemus, they prefer the lower part of their tank; the pectoral and tail fins are 

 moved most, but there seems less of the constant waving of fins about this species 

 than there is with the other two Mormyridse [Marcusmius isidori and Gnathonemus 

 cyprinoides] mentioned above." 



Unless the insufficiently defined M. hildebrandti, Peters *, from the Athi River, 

 Ukamba, be regarded as identical with it, M. Jcannume appears to be confined to the 

 Nile in its widest sense, including Lake Victoria. A young specimen collected in the 

 Wabbi River (Webi Shebeli system) by Mr. Oscar Neumann and the late Baron Carlo 

 von Erlanger has been referred by me f to this species, but as it has only 51 rays in 

 the dorsal fin, its determination is still doubtful. 



The passage from M. Jcannume to M. caschive is a very complete one, the shorter 

 dorsal fin with 57 to 75 rays instead of 76 to 90 being, so far as I can see, the safest 

 diagnostic character of the former species. I have counted the dorsal fin-rays in sixty 

 specimens, and find 57, 58, 68, 71, and 75 to occur once, 59, 60, 70, 73, and 74 twice, 

 64 and 66 five times, 61 and 67 six times, 63 and 65 seven times, and 62 nine times. 



18 anal rays occur ten times, 19 twenty-two times, 20 twenty-six times, and 21 twice. 

 List of specimens examined : — 



2 Nile.— Rev. 0. P. Cambridge, 1864. 

 1 Lower Nile. — Ruppell, 1833. 



1 Lower Nile.— E. Lort Phillips, 1892. 



1 Nile at Cairo.— Dr. F. Werner, 1899. 



10 Nile at Cairo.— Loat, 15-17.6.00. 



1 Nile at Cairo.— Capt. Flower, 1905. 



3 Boulak Fish Bazar, Cairo.— Loat, 15-19.3.99. 

 8 Beni Souef.— Loat, 27.8.— 9.10.99. 



3 Samhur, near Beni Souef. — Loat, 5.9.99. 



19 Between Beni Souef and Biba. — Loat, 6-7.9.99. 

 1 Akhmim.— Loat, 13.12.99. 



1 Girgeh.— Loat, 14.12.99. 

 3 Luxor.— Loat, 25-28.10.00. 



* Sitzb. Ges. naturf. Fr. Berlin, 1882, p. 73. 

 f Proc. Zool. Soc. 1903, ii. p. 328. 



