MICBALESTES. 



131 



3. MICEALESTES. 



Brachyalestes, part., Giinther, Cat. Fish. v. p. 314 (1864). 



Aficralestes, Boulenger, Ann. Mus. Congo, Zool. i. p. 87 (1899), and Poiss. Bass. Congo, p. 160 



(1901). 



Eig. 20. 



Differs from Alest.es in all the teeth of the upper jaw being simply 

 compressed and tri- to septemcuspid. 



All the species are small, with the body short and covered with large 

 scales bearing one or two longitudinal canals. The air-bladder is 

 not produced beyond the body-cavity, and the digestive canal is short. 

 Skull with a large fontanelle ; supraorbital bones large. Vertebrae 34 

 (18+16). 



The type of this genus, M. acutidens, is widely distributed in Tropical 

 Africa and has lately been ascertained to occur in the Nile. Five other 

 species are known from the Congo. 



1. MICPALESTES ACUTIDENS. 

 (Plate XIX. figs. 3 & L) 



Alestes acutidens, Peters, Mon. Berl. Ak. 1852, p. 276, and Peise Mossamb. iv. p. 64, pi. xii. fig. 2 



(1868). 

 Brachyalestes acutidens, Griinther, Cat. Fish. v. p. 316 (1864). 

 Micralestes acutidens, Boulenger, Ann. Mus. Congo, Zool. i. p. 87 (1899), and Proc. Zool. Soc. 



1903, ii. p. 329. 



Body strongly compressed, its depth three to three and three-fourths times in the 

 total length ; length of head three and a half to four and one-fifth times. Head twice 

 to twice and a half as long as broad, a little longer than deep ; snout rounded, shorter 

 than the eye, which is perfectly lateral ; diameter of the eye twice and one-third to 

 three times in the length of the head, equal to the interorbital width, and greater than 

 the width of the mouth ; maxillary extending nearly to below the anterior border of 



fi 8 



the eye ; 14 teeth (g) in the upper jaw, 10 (g) in the lower ; lower border of second 

 suborbital not longer than the eye. Gill-rakers short, 12 to 15 on lower part of 

 anterior arch. Dorsal fin with II 8 rays, beginning above the base of the ventrals, 

 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 



s2 



