312 CHARACINID.E. 



dark band runs from the end of the operculum to the lower half of 

 the base of the caudal fin. 

 British Guiana. 



a. Five inches long. Presented by Sir R. Schomburgk. 



17. ALESTES. 



Alestes, sp., Mull. $■ Trosch. Hor. Ichth. i. p. 12. 

 Alestes et Brycinus, Cuv. ty Val. 



The dorsal fin is placed in the middle of the length of the body, 

 behind the ventrals ; anal fin rather long. Body oblong, covered 

 with scales of moderate or large size ; belly rounded. Cleft of the 

 mouth rather small. Maxillary teeth none ; intermaxillary teeth in 

 two series : those of the front series more or less compressed, more 

 or less distinctly tricuspid ; the teeth of the hinder series are broad, 

 molar-like, each armed with several pointed tubercles. Teeth in the 

 lower jaw in two series : those in the front series laterally compressed, 

 broader behind than in front ; the hinder series is composed of two 

 conical teeth. All the teeth are strong, few in number. Nostrils 

 close together, separated by a valve only. Gill-opening wide, the 

 gill-membranes being united for a short space only, and not grown 

 to the isthmus. 



Tropical Africa. 



The species may be brought into two groups : — 



* Scales of moderate size : Akstes, m. 

 * * Scales veiy large : Brycinus, Val. 



* Scales of moderate size. 



1. Alestes dentex. 



Raches. 



Salmo dentex, Hasselq. Reise Palast. p. 437. 



niloticus, Forsk. Descript. Anim. p. 66. no. 976. 



Characinus niloticus, Geoffr. St.-Hil. Descr. Eg. Poiss. pi. 4. fig. 2. 

 Myletes hasselquistii, Cuv. Mem. Mus. iv. p. 449. pi. 21. fig 2. 

 41estes dentex, Mull. $ Trosch. Hor. Ichth. i. p. 13. pi. 2. fig. 6 (den- 

 tition) ; Heckel, in Russegger, Reise, ii. part 3. p. 307. +af. 21. fig. 2. 

 hasselquistii, Cuv. Sf Val. xxii. p. 180. 



D. 10. A. 23-24. V. 10. L. lat. 45. L. transv. 9/3*. Vert. — . 



' A 18 20 



The height of the body is a little more than one-fourth of the total 

 length (without caudal), the length of the head one-fifth. Teeth of 

 moderate strength, not coloured. Body silvery. 



Nile. 



a-c. Fine specimens. Chartoum. From Consul Petherick's Collection. 



d. Half-grown : skeleton. Chartoum. From Consul Petherick's 



Collection. 



e. Adult: skeleton. Lower Nile. From Dr. Ruppell's Collection. 



