45. SERRASALMO. 309 



5. Serrasalmo niger. 



Serrasalmo niger, Schomburak, Fish. Brit. Guiana, i. p. 225. tab. 18. 

 Pygocentrus niger, Mutt, fy Trosch. Hor. Ichth. i. p. 21. tab. 2. fig. 3 

 (dentition) ; Cuv. ty Val. xxii. p. 286. 



D. 18. A. 33-35. L. lat. 105. 



The height of the body is contained twice and one-ninth in the 

 total length (the caudal included); snout very obtuse, short; the 

 width of the interorbital space is only a little less than one-half of 

 the length of the head. The second infraorbital bone touches the 

 praeopercular limb. Abdominal serrature composed of forty spinous 

 plates. Gill-rakers of the outer branchial arch very short and broad. 



Guiana. 



6. Serrasalmo nattereri. 



Kner, Denkschr. Acad. Wiss. Wien, 1860, xviii. p. 36. taf. 3. fig. 8. 

 D. 16-18. A. 27-30. 



The height of the body is nearly one-half of the total length (with- 

 out caudal) ; snout very obtuse and short ; the width of the inter- 

 orbitai space is a little more than one-half of the length of the head. 

 The second infraorbital bone nearly touches the praeopercular limb. 

 The origin of the dorsal fin is considerably nearer to the root of the 

 caudal fin than to the end of the snout. Abdominal serrature com- 

 posed of from twenty-two to twenty-rive spinous plates. Gill-rakers 

 of the outer branchial arch elongate, hooklike. {Kner.) 



Matogrosso and Cujaba. 



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

 Serrasalmo, Lace"p. 



7. Serrasalmo rhombeus. 



Salmo . rhombeus, L. Syst. Nat. i. p. 514; Block, taf. 383; Bl. Schn. 



p. 404 ; Pall. Spicil. Zool. fasc. viii. p. 57. tab. 5. fig. 3. 

 Serrasalmo rhombeus, Lacep. v. p. 284 ; Cuv. Mem. Mus. v. p. 367 ; 



Cuv. 8f Val. xxii. p. 272 ; Casteln. Anim. Amer. Sud, Poiss. pi. 37. 



fig. 3 fbad). 



D. 18. A. 34. V. 7. L. lat. 100. 



The height of the bodyis one-half or somewhat less than one-half 

 of the total length (without caudal), the length of the head one-third ; 

 snout subcorneal, much longer than the eye. The second infraorbital 

 is nearly as high as long, and more or less in contact with the prae- 

 opercular limb. Abdominal serrature composed of from twenty-nine 

 to thirty spinous plates. Gill-rakers of the outer branchial arch very 

 short, terminating in a small point. Body with small blackish spots ; 

 an indistinct blackish blotch behind the gill- opening ; caudal fin 

 with the posterior margin black. 



Guianas, Brazil. 

 a. Fine specimen. Essequibo. Purchased of Mr. Ehrhardt. 

 b-c. Adult. Surinam. From the Stuttgart Museum. 



d. Half-grown. Surinam. Purchased of Mr. Frank. 



e. Adult : stuffed. Demerara. Purchased of Mr. Scrivener. 



2u 



