246 
TEAVELS IN CENTEAL AFEICA. 
smaller similar teeth behind the front series; palate toothless. 
Nostrils close together,, with a valve between them^ overlapping the 
posterior. Gill- openings of moderate widths the gill membranes 
being attached to the isthmus^, having a free hinder edge nearly 
along their entire extent. 
Distichodus niloticus, Hasselq. 
D. 24—26. A. 14—15. V. 11. L. lat. 103—105. 
L. transv. 20/19. 
The height of the body is two-fifths or less than two-fifths of the 
total length (without caudal) in mature specimens, and only one- 
third in young ones. The length of the head is contained four times 
and two-thirds or four times and three-fourths in that of the body 
in mature specimens, hut it is one-fourth of it in young ones. Snout 
obtuse ; interorbital space broad, depressed, not very convex. The 
lower jaw with about thirty-six teeth in the front series; young 
individuals have less. The anal fin extends backwards to, or nearly 
to, the root of the caudal, if laid backwards. Silvery, hack greenish ; 
dorsal fin with short, oblique, narrow blackish streaks on the inter- 
radial membrane. Young specimens with a blackish spot behind 
the head, between the lateral line and the gill-opening, and with 
several indistinct transverse blackish blotches on the body. 
Attains to a weight of nearly 100 pounds, and is very good eating. 
Distichodus rostratus, Gthr. (Plate III., Pig. B.) 
D. 23—25. A. 14. V. 11. L. lat. 89—98. L. transv. 16/16. 
The height of the body is contained thrice and one-fourth in the 
