HYDKOCYON. 101 



peduncle once and two-thirds to twice as long as deep. Scales 48-54 ^i, 3 between 

 lateral line and ventral, 2 between lateral line and scaly process at base of ventral fin. 



The back is grey, brown, or olive-green, the sides and the belly are silvery white; 

 more or less distinct longitudinal rows of blackish spots, often confluent into streaks, 

 run along the series of scales above the lateral line, and, exceptionally, also along the 

 series bordering the lateral line below, such specimens, which in this character agree 

 with if. lineatus, being from Lake Albert, the White Nile, and the Senegal. These 

 spots or streaks are entirely absent in very young specimens. The dorsal tin and the 

 upper lobe of the caudal are yellowish or grey, often blackish towards the end ; the 

 adipose fin is grey or whitish, rarely with a black spot * ; the ventral and anal fins, 

 and sometimes also the pectorals, are tinged with pink or pale orange ; the lower lobe 

 of the caudal, which fin is often edged with black, is bright red. Iris silvery 

 or bronzy. 



The proportions of the body vary considerably, as may be seen from the following 

 table of measurements. As to the variations in the numbers of anal rays and of scales 

 in the lateral line, out of one hundred specimens I have recorded seven with 11 

 branched anal rays, eighty-two with 12, and eleven with 13 ; two with 48 scales in the 

 lateral line, six with 49, twenty-nine with 50, thirty with 51, eighteen with 52, ten 

 with 53, and five with 54. 



The largest specimen measures 450 millimetres, but the fish is said to grow to a 

 much greater size f . 



Hydrocyon forskalii is known from the Nile, the Blue Nile, the White Nile, the 

 Senegal, the Niger, Lake Rudolf, and Lake Gandjule (Margherita). In the Lower 

 Nile it occurs chiefly during flood time. 



The following is a list of the specimens examined : — 



1 Egypt.— Riippell, 1833. 



1 Lower Nile.— Petherick, 1861. 



1 Lake Edkou.— Loat, 29.10,99. 



1 Damietta branch of Nile, downstream side of Barrage. — Loat, 3.8.99. 



1 Nile near Cairo, upstream side of Barrage. — Loat, 4.9.99. 



1 Trench near Cairo.— Loat, 21.10.99. 



2 Nile near Old Cairo, bought in Old Cairo Fish-bazar. — Loat, 4.4.99. 

 4 Nile near Cairo, bought in Boulak Fish-bazar. — Loat, 20.3.99. 



1 Canal in Zoological Gardens, Giza. — Loat, 21.3.99. 

 1 Wasta.— Loat, 28.8.99. 

 17 Beni Souef.— Loat, 8-9.99. 



* This I have only observed in two specimens from the Niger. 



t A head from the Senegal indicates a probable total length of nearly a metre. 



