366 CnARACINID^. 



Tenth Group. SERRASALMONINA. 

 Characinidse with an adipose fin and with the dorsal rather 

 elongate, with the gill-membranes free from the isthmus, and 

 with the belly serrated. 



South America. 



44. MYLESINUS. 



Mylesinus, Cuv. 8f Val. xxii. p. 234. 



Dorsal fin rather elongate, placed behind the middle of the length 

 of the body, above the interspace between ventrals and anal ; anal 

 fin long. Head and body compressed, elevated, covered with very 

 small scales ; beUy rounded in front of the ventrals, keeled and ser- 

 rated behind them. Cleft of the mouth of moderate width : teeth 

 large, compressed, three-lobed : those of the intermaxillary in two 

 series which are close together, those of the mandible in a single 

 series, without a pair of posterior conical teeth. 



Guiana, Brazil. 



1. Mylesinus schomhurgkii. 



Cuv. Sf Vol. xxii. p. 235. pi. 044 ; Kner, Denkschr. Acad. Wiss. Wien, 

 1860, xviii. p. 32. taf. 3. fig. 7. 



Valenciennes describes this species from a head and from a drawing, 

 both having been given to him by Schomburgk. According to the 

 drawing, the principal specific characters would be : a body the depth 

 of which is rather more than one-half of the total length (the caudal 

 fin not included), a short adipose fin, and an anal fin the posterior 

 half of which is produced into a lobe. 



If this drawing be correct, the fish described and figured by Kner, 

 from specimens from the Rio Vaupe, cannot be identical with that 

 found by Schomburgk, the lobe of the anal fin being formed by the 

 middle rays. Kner adds other characters : D. 21-22. A. 32-35. 

 V. 8. The height of the body is one-half of the total length (without 

 caudal), the length of the head one-fourth ; the abdominal serrature 

 behind the ventrals is formed by from eight to ten osseous plates ; 

 each of the fifteen or sixteen posterior anal rays terminates in two 

 branches, one being bent towards the right, the other to the left. 



45. SERRASALMO*. 



Serrasalmus, Lacip. v. p. 283. 



Pygocentrus, Pygopristis, et Serrasalmo, Midi. ^ Trosch. Hor. Ichth. 

 i. pp. 20 & 21. 

 Dorsal fin rather elongate, placed behind the middle of the length 



* 1. Pygocentrus palometa, C. ^ F. rxii. p. 296. — Mouth extremely small ; eyes 

 very large ; dorsal fin falciform, opposed to the ventrals; pectorals and 

 ventrals very small. — Brazil. 

 2. Serrasalmo, Humb. Ohserv. Zool. ii. p. 173. pi. 47. fig. 1 ; Serrasalmus 



caribe, C. &f V. xxii. p. 279. — Orinoco. 

 .3. Serrasalmo gibbus, Gasteln. Anim. Amer. 8ud, Poiss. p. 71. pi. 38. fig. 1. 

 — Araguay. 



