384 MEMOIRS OF THE CARNEGIE MUSEUM 



237. Pygocentrus niger (Schomburgk). 



Serrasalmo niger Schomburgk, Fishes Brit. Guiana, I, 1841, 225, pi. 18 (in streams 

 between forty and one hundred and fifty miles from coast). — Gunther, 

 Catalogue, V, 1864, 369. 



Pygocentrus niger Muller and Troschel, Hora? Ichth., I, 1845, 21, pi. 2, fig. 3.— 

 Cuvier and Valenciennes, Hist. Nat. Poiss., XXII, 1848, 286 (Corentyn). — 

 Muller and Troschel, in Schomburgk, Reisen, III, 1848, 636 (upper courses 

 of all streams). — Eigenmann and Eigenmann, Proc. U. S. Nat. Mus., XIV, 

 1891, 59. — Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 442. 

 No specimens of this species were secured. It is said to be very abundant 



and the most voracious of the "Perais." I have examined the specimen figured 



by Muller and Troschel. It has forty abdominal serrae and its depth is equal to 



half the length. 



238. Pygocentrus piraya (Cuvier). 



"Piraya," Marcgrave, Hist, Rer. Nat. Bras., 1648, 164. 



Serrasalmo piraya Cuvier, Mem. Mus. d'Hist. Nat,, V, 1819, 368, pi. 28, fig. 4- 

 Gunther, Catalogue, V, 1864, 368 (Brazil; River Cupai; Demerara).— 

 Cope, Proc. Am. Philos. Soc, XI, 1870, 566 (Para).— Steindachner, "Fluss- 

 fische Sudamerika's," ii, 1881, 13 (Teffe; Rio Puty). — Perugia, Ann. Mus. 

 Genova, (2a), X, 1891, 51 (Villa Maria; Matto Grosso; Rio Paraguay). 



Pygocentrus piraya Muller and Troschel, Horse Ichth., I, 1845, 20. — Cuvier 

 and Valenciennes, Hist. Nat. Poiss., XXII, 1848, 291. — Muller and Tro- 

 schel, in Schomburgk, Reisen, III, 1848, 636 (generally distributed in Brit. 

 Guiana). — Kner, "Familie der Characinen," ii, 1859, 28. — ? Castelnau, 

 Anim. Am. Sud, Poiss., 1855, 72, pi. 38, fig. 2 (Goyaz; Amazon). — Eigenmann 

 and Eigenmann, Proc. U. S. Nat. Mus., XIV, 1891, 59.— Ulrey, Ann. N. Y. 

 Acad. Sci., VII, 1895, 297 (Trocera on Tocantins). — Fowler, Proc. Acad. Nat. 

 Sci. Phila., 1906, 468 (Para). — Eigenmann, Repts. Princeton Univ. Exp. Pata- 

 gonia, III, 1910, 442. 



Serrasalmo (Pygocentrus) piraya Lutken, Dan. Vidensk. Selsk. Skr., (5), XII, 2, 

 1875, 233 and xvii (Rio das Velhas). 



Serrasalmo piranha Agassiz, Selecta Gen. et Spec Pise. Bras., 1829, 71, pi. 28. — 

 Schomburgk, Fishes Brit. Guiana, I, 1841, 221, pi. 16 (Rio Branco). 



Serrasalmo nigricans* 1 Agassiz, Selecta Gen. et Spec. Pise. Bras., 1829, 72, pi. 30.— 



Muller and Troschel, in Schomburgk, Reisen, III, 1848, 636 (generally 



distributed in British Guiana). 



67 Lutken ( Vidensk. Med. Nat. For. Kjobenhavn, 1874, 238) considers this a distinct species. The 

 specimen mentioned by Muller and Troschel, and now in the Berlin Museum, is P. piraya. 



