360 charactnid^:. 



a. Each jaw with two series of teeth. 



1 . Distichodus niloticus. 



Salmo ni 1 jticus, Hasselq. Reise, p. 422. 

 Nefasch, Forsk. Descript. Anim. p. 66. 

 Salmo aegyptiacus, L. Gm. i. p. 1386. 



aegyptius, Bl. Schn. p. 418. 



Characinus nefasch, Lacep. v. pp. 272, 274 ; Geoffr. Descr. Eg. Poiss. 



pi. 5. fig. 1. 

 Distichodus niloticus, Mull. § Trosch. Hor. Ichth. i. p. 12. tab. 1. fig. 3 



(dentition). 

 nefasch, Cuv. fy Vol. xxii. p. 175. 



B. 4. D. 24-26. A. 14-15. Y. 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, but 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 in- 

 dividuals have less. The anal fin extends backwards to, or nearly 

 to, the root of the caudal, if laid backwards. Silvery, back 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. 



Upper and Lower Nile. 

 a. Fine specimen, 30 inches long. Lower Nile. From Consul 



Petherick's Collection. 

 b-d. Young. Lower Nile. From Consul Petherick's Collection. 

 e-m. Adult, half-grown, and young. Upper Nile. From Consul 



Petherick's Collection. 

 n. Half-grown : skin, in spirits. Egypt. Presented by J. Burton, 



Esq. 



2. Distichodus rostratus. 



D. 23-25. A. 14. Y. 11. L. lat. 89-98. L. transv. 16/16. 



The height of the body is contained thrice and one-fourth in the 

 total length (without caudal), the length of the head four times and 

 three-fourths. Snout rather pointed ; in a specimen 14 inches long 

 it is more than twice as long as the eye ; interorbital space broad, 

 convex, its width: being contained twice and one-third in the length 

 of the head. The lower jaw with about twenty-eight teeth. The 

 anal fin extends somewhat beyond the root of the caudal, if laid 

 backwards. Silvery, back greenish, sides clouded with blackish; 

 dorsal fin with small blackish spots. 



This species is otherwise similar to D. niloticus, from which it will 

 be readily distinguished by its prominent nose, fewer scales on the 

 back, and long anal fin; we are not quite certain whether the sped- 



