HTDROCYON.— BEYCON^TllIOPS. 187 



to the region above the lateral line ; a black spot sometimes present on 

 adipose fin. 



Total length 480 millira. 



Lower Nile to White Nile, Chad Basin, Senegal, Gambia. 



1-2. Ad. & hcrr. Lower Nile. J. Petlierick, Esq. (C ). 



3-12, 13-22, 23-30. Hgr. Near Luxor. L. Loat, Esq. (C). 

 & yg. 

 31. Skel. 



32-34. Types. Khartum, J. Petherick, Esq. (C). 



35. Ad. Lake Chad. Capt. G. B. Go.-ling (P.). 



36. Ad. Shari R. at Maidiigari. „ 



37. Ad. Matam, Senegal. M. P. Delhez (C). 

 38-42, Ad. & hgr. McCarthy I., Gambia. J. S. Budgett, Esq. (P.). 



3. BRYCON.S]THIOPS. 



Glinth. Ann. & Mag. N. H. (4) xii, 1873, p. 143 ; Bouleng. Poiss. Bass. Congo, 

 p. 145 (1901). 



Snout short ; mouth moderately large ; prsemaxillaries immovable, with 

 3 series of large pluricuspid teeth, those of the inner series with hollowed- 

 out, tubercular crowns ; maxillary large, toothless ; a series of large, 

 compressed, pluricuspid teeth in the lower jaw, with a pair of conical 

 teeth behind them. Cheek covered by the large suborbitals ; nostrils 

 near the eye, close together, separated by a valvular flap ; gill-membranes 

 free from isthmus ; 3 branchiostegal rays. Body moderately elongate, 

 compressed ; belly rounded. Scales moderately large, not ciliated ; 

 lateral line nearer the ventral than the dorsal outline ; a scaly process at 

 the base of the ventral fin. Dorsal fin with 10 rays, originating in 

 advance of ventrals ; anal with 20-23 rays; a small adipose dorsal fin. 

 Vertebra 38 (19 + 19). 



Tropical Africa. 



Two species : — 



Head longer than deep i longest ra3'S of dorsal 



not or but little longer than head; 65 series 



of scales above lateral line 1. J3. microstoma, Gthr., p. 188. 



Head as long as deep ; some of the rays of dorsal 



much prolonged ; 7^ series of scales above 



lateral line 2. B. Jjseu.vi, Blgr., p. 189. 



