ALESTES. 123 



longer than deep; snout rounded, not or but slightly projecting beyond the lower lip, 

 not longer than the eye ; eye lateral, visible from above and from below, its diameter 

 twice and a half (young) to four times in the length of the head; interorbital region 

 moderately convex, its width twice and one-fourth to twice and three-fifths in the length 

 of the head ; width of mouth equal to or a little less than the diameter of the eye ; 

 maxillary not reaching to below the anterior border of the eye ; 14 or 16 teeth (^) in 

 the upper jaw, 10 (|) in the lower; lower border of the second suborbital longer than 

 the eye in the adult. Gill-rakers moderately long, 16 to 20 on the lower part of the 

 anterior arch. Dorsal with II 8 rays (7 in one specimen, from Luxor), beginning 

 above the base of the ventrals, equally distant from the centre or the posterior border 

 of the eye and from the root of the caudal fin ; first branched ray longest, as long as or 

 a little shorter than the head. Adipose fin small, twice and one-third to twice and 

 two-thirds as far from the rayed dorsal as from the root of the caudal. Anal fin with 

 III 11-15 rays, anterior rays longest in the females, median rays longest in the males, 

 the border of the fin being more or less convex or angular in the latter. Pectoral fin 

 a little shorter than the head, not reaching the ventral ; latter shorter. Caudal fin 

 deeply forked, the lobes pointed. Caudal peduncle once to once and a half as long as 

 deep. Scales with radiating and with more or less distinct arborescent or anastomosing 

 canals, 26-33 if, 2 between the lateral line and the root of the ventral fin. 



Silvery or pale golden, dark grey or brown on the back, which may be shot with 

 reddish bronze ; sides often tinged with pinkish or pale lilac ; sometimes a blackish 

 spot above the lateral line, behind the gill-opening, and another on the caudal 

 peduncle, sometimes extending as a streak along the median rays of the caudal fin; 

 dorsal fin greyish, usually with a little pink or red ; ventrals and anal white at the 

 base, usually with a band of red ; adipose fin sometimes tipped with orange or red ; 

 caudal fin orange or red, the base and the edge blackish ; iris silvery or golden. 

 According to Mr. Degen, the black spot at the base of the caudal fin, in Lake 

 Victoria specimens, is of a brilliant orange in life. 



The largest specimen from the Nile (Rosairesj measures 195 millimetres. A 

 specimen from the Senegal measures 230. 



Out of fifty specimens from various parts of Africa (excepting L. Victoria) in which 

 I have counted the fin-rays and scales, one (from the Senegal) has 11 branched rays 

 in the anal fin, nine have 12, nineteen have 13, twenty-one have 14; one specimen 

 (from the Gold Coast) has 26 scales in the lateral line, three have 27, four have 

 28, six have 29, eleven have 30, seventeen have 31, seven have 32, and one (from 

 Luxor) has 33. Specimens from Lake Victoria have 14 or 15 branched anal rays, 

 and 26 to 30 scales in the lateral line. 



The variations in form are very considerable, irrespective of age and localities. 

 The spots on the body are also very inconstant, as already pointed out by de Joannis, 



r2 



