EIGENMANN: THE FRESHWATER FISHES OF BRITISH GUIANA 411 



264. Acestrorhynchus nasutus sp. nov. (Plate LXI, fig. 4.) 



Type unique, 79 mm. Rockstone. (Carnegie Museum Catalog of Fishes 

 No. 1959.) 



Distinguished by its long soft-tipped snout, short frontal fontanel, lateral 

 bands, long head, etc. 



Head 3.1; depth G; D. 11; A. 27; scales 79, eight between lateral line and 

 anal; eye 2.33 in the snout, 3.7 in the head, .7 in the interorbital. 



Frontal fontanel very short, not reaching forward to above middle of eye; 

 tip of snout soft. 



A dark stripe from the tip of the snout to the end of the middle caudal rays; 

 no humeral spot; a distinct enlargement of the band into a caudal spot; a second 

 dark band from the end of the anal forward to above the space between the anal 

 and ventrals. 



Subfamily Hydrocynin^e. 



Hydrocynus Cuvier. 

 Hydrocynus Cuvier, Regne Animal, II, 1817, 167. 

 Xiphostoma Spix, Selecta Gen. et Spec. Pise. Bras., 1829, 78, pi. 42. 



Type, Hydrocynus lucius Cuvier. 



Lepidosteus-like Characins, the snout prolonged into a beak; each jaw with 

 a series of minute conical teeth; dorsal in posterior half of the body; scales dentic- 

 ulate on the margin; lateral line complete. 



One of the four species of the genus is locally abundant in Guiana. 



265. Hydrocynus cuvieri (Agassiz). 



Xiphostoma cuvieri Agassiz, Selecta Gen. et Spec. Pise. Bras., 1829, 78, pi. 42.— 

 Miller and Troschel, Horse Ichth., I, 1845, 20, pi. 3, fig. 3 (Brazil and Gui- 

 ana). — Cuvier and Valenciennes, Hist. Nat. Poiss., XXII, 1848, 355 (Ama- 

 zon). — Muller and Troschel, in Schomburgk, Reisen, III, 1848, 636 (Upper 

 Essequibo, Takutu; Rupununi). — Kner, "Familie der Characinen," ii, 1859, 

 pi. 8, fig. 17 (Marabitanos). — Gunther, Catalogue, V, 1864, 357. — Eigen- 

 mann and Eigenmann, Proc. U. S. Nat. Mus., XIV, 1891, 59. — Pellegrin, 

 Bull. Mus. d'Hist. Nat,, V, 1899, 157 (Apure).— Eigenmann, Repts. Princeton 

 Univ. Exp. Patagonia, III, 1910, 446. 



Xiphostoma oceUatum Schomburgk, Fishes Brit. Guiana, I, 1841, 245, pi. 18 

 (Essequibo; Rios Negro and Branco). 



Xiphostoma oseryi Castelnau, Anim. Am. Sud, Poiss., 1855, 76, pi. 40, fig. 1 

 (Tocantins) . 



