45. SERBASALMO, 367 



of the body, between ventrals and anal ; anal long. Head and body 

 compressed, more or less elevated, covered with very small scales ; 

 belly keeled, serrated. Cleft of the mouth of moderate width : teeth 

 large, compressed, sharp, pointed, with more or less lateral lobes, in 

 a single series in the intermaxillary and mandible ; none in the 

 maxillary, which is short. Gill-openings very wide, the gill-mem- 

 branes being slightly united below the throat. Intestinal tract with 

 a single circumvolution. 

 Brazil, Guianas. 



The species have been referred to the following subgeneric groups : 



• No teeth on the palate ; teeth in the jaws serrated : Pygopristis, 

 M. & T., p. 367. 



•* No teeth on the palate ; teeth in the jaws simply cutting : Pygocen- 

 trus, M. & T., p. 368. 



*** A more or less complete series of teeth on each side of the palate : 

 Serrasalmo, Lac^p., p. 369. 



* No teeth on the palate ; teeth in the jaws serrated : Pygopristis, M. & T. 



1. Serrasalmo denticulatus. 



Serrasalmo denticulatus, Cuv. Mem. Mus. v. p. 371. 



punctatus, Schomburgk, Fish. Chdana, i. p. 223. taf. 17. 



Pygopristis denticulatus, Midi. ^ Trosch. Hor. Ichth. i. p. 34. tab. 9. 



fig. 1 (young) ; C(«'. Sf Val. xxii. p. 297. 

 fumarius, Miill. Sf Trosch. I. c. p. 35. tab. 9. fig. 2; Kner, Denkscfir. 



Acad. Wiss. Wien, 1860, xviii. p. 35. 



B. 4. D. 19. A. 35. V. 7. 



The height of the body is contained once and two-thirds in the 

 total length (without caudal), the length of the head nearly four 

 times ; snout obtuse, about as loil^ as the eye. The second infra- 

 orbital bone is separated from the prseopercular limb by a naked 

 space, which is nearly as wide as the infraorbital. Abdominal ser- 

 rature composed of from thirty to thirty-four spinoiis plates. The 

 length of the adipose fin is two-sevenths of that of the dorsal ; none 

 of the fiin-rays prolonged. 



Guiana. 



a, h, c. Adult and half-grown. British Guiana. Presented by Sir 

 R. Schomburgk and Dr. Hancock. 



2. Serrasalmo serrulatus. 



Pygopristis serrulatus, Cuv. ^- Val. xxii. p. 300 ; Casteln, Anim. AmSr. 

 Slid, Poiss. pi. 38. fig. 3. 



D. 16. A. 33. 

 The height of the body is one-half of the total length, the caudal 

 included. Adipose fin small; none of the fin-rays are prolonged. 

 Vertical fins vrith blackish margins. 

 Araguay, Amazons. 



