eigenmann: the FRESHWATER FISHES OF BRITISH GUIANA 385 



Pygocentrus bidorsalis (ex Natterer, MS.) Kner, "Familie der Characinen," ii, 



1854, 28. 



Thirteen specimens, 84-109 mm. Twoca Pan. (C. M. Cat. No. 1096a-d; 

 I. U. Cat. No. 11639.) Collected by Wm. Grant. 



239. Pygocentrus scapularis (Gunther). 



Serrasalmo scapularis Gunther, Catalogue, V, 1864, 268 (British Guiana). — 

 Pellegrin, Bull. Mus. d'Hist. Nat., V, 1899, 157 (Apure). 



Pygocentrus scapularis Eigenmann and Eigenmann, Proc. U. S. Nat. Mus., XIV, 

 1891, 69.— Ulrey, Ann. N. Y. Acad. Sci., VII, 1895, 297 (Marajo).— ? Eigen- 

 mann and Ogle, Proc. U. S. Nat. Mus., XXXIII, 1907, 35 (South Amer- 

 ica). — Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 442. 

 One specimen, 42 mm. Wismar. (C. M. Cat. No. 1110.) 

 Twelve specimens, 29-44 mm. Rockstone. (C. M. Cat. No. 1104a-<2; 



I. U. Cat. No. 11644.) 



Three specimens, 159-184 mm. Crab Falls. (C. M. Cat. No. 1135a; I. U. 



Cat. No. 11638.) 



240. Pygocentrus bilineatus Eigenmann. (Plate LVI, fig. 2.) 



Pygocentrus bilineatus Eigenmann, Ann. Carnegie Mus., VI, 1909, 47; Repts. Prince- 

 ton Univ. Exp. Patagonia, III, 1910, 442. 

 Type, 102 mm. Aruka River. (C. M. Cat. No. 1072.) 

 Cotypes, 95-110 mm. Aruka River. (C. M. Cat. No. 1073; I. U. Cat. No. 



11756.) 



Cotypes, 43-56 mm. Mora Passage. (C. M. Cat. No. 1074; I. U. Cat. No. 



11757.) 



Pygopristis Mtiller and Troschel. 



Pygopristis Muller and Troschel, Horse Ichth., I, 1845, 21, pi. 9, figs. 2a and 2b. 



Type, Pygopristis fumarius Muller and Troschel (= denticulatus Cuvier). 



Belly trenchant, serrate; premaxillary with a single series of teeth; no teeth 

 on the palate; teeth in the jaws serrate or lobed; anal naked except at its base; a 

 procumbent dorsal spine. 



241. Pygopristis denticulatus (Cuvier). 

 Serrasalmo denticulatus Cuvier, Mem. Mus. d'Hist. Nat., V, 1819, 371. — Gunther, 



Catalogue, V, 1864, 367 (British Guiana). 

 Pygopristis derdiculatus Muller and Troschel, Horse Ichth., I, 1845, 21, 34, pi. 



9, fig. 1 (Guiana); in Schomburgk, Reisen, III, 1848, 637 (Essequibo ; Takutu ; 



