410 MEMOIRS OF THE CARNEGIE MUSEUM 



263. Acestrorhynchus falcirostris (Cuvier). 



Hydrocyon falcirostris (.uvier, Mem. Mus. d'Hist. Nat., V, 1819, 361, pi. 27, fig. 3. 



Xiphorhynchus falcirostris AoASSiz, Selecta Gen. et Spec. Pise. Bras., 1829, 76. 



Xiphorhamphus falcirostris Muller and Troschel, Horse Ichth., I, 1845, 18. — 

 Kner, "Familie der Characinen," ii, 1859, 50 (Matto Grosso). — Gunther, 

 Catalogue, V, 1864, 354 (Demerara; River Cupai); Proc. Zool. Soc. London, 

 1868, 247 (Xeberos; Pebas).— Cope, Proc. Am. Philos. Soc, XVII, 1878, 

 688 (Peruvian Amazon). — Steindachner, "Flussfische Siidamerika's," iv, 

 1882, 15 (Huallaga). — Eigenmann and Eigenmann, Proc. U. S. Nat. Mus., 

 XIV, 1891, 58. 



Acestrorhynchus falcirostris Fowler, Proc. Acad. Nat. Sci. Phila., 1906, 462. — 

 Eigenmann and Ogle, Proc. U. S. Nat. Mus., XXXIII, 1907, 35.— Eigen- 

 mann, Repts. Princeton Univ. Exp. Patagonia, III, 1910, 447. 



Hydrocyon armatus Schomburgk, Fishes Brit. Guiana, I, 1841, pi. 25, not descr. 

 One specimen, 140 mm. Malali. (C. M. Cat. No. 1909a.) 

 Four specimens, 157-357 mm. Malali. (C. M. Cat. No. 1996a-6; I. U. 



Cat. No. 12337.) 



Two specimens, about 170 mm. Twoca Pan. (C. M. Cat. No. 1978a; 



I. U. Cat. No. 12237.) 



Two specimens, 335-342 mm. Maduni Creek. (C. M. Cat. No. 1990o; 



I. U. Cat. No. 12238.) 



One specimen, 205 mm. Wismar. (C. M. Cat. No. 1991a.) 



Twelve specimens, 150-340 mm. Rockstone. (C. M. Cat. No. 1992a-c; 



I. U. Cat. No. 12239.) 



Two specimens, 270-315 mm. Lama Stop-Off. (C. M. Cat. No. 1993a; 



I. U. Cat. No. 12240.) 



Two specimens, 237-238 mm. Konawaruk. (C. M. Cat. No. 1994a; I. U. 



Cat. No. 12241.) 



Head 3.33-3.6; depth 6-7; D. 11; A. 22-26; lateral line 144-152, sixteen 



scales between lateral line and origin of anal. Eye 2-2.25 in the snout, 5-5.5 



in the head, 1-1.5 in the interorbital. 



Fontanel not extending forward to middle of eye. 



No shoulder-spot; a small, circular, well-defined, intense black caudal spot; 



upper part of opercle blackish; pectoral and caudal yellowish in life, the middle 



caudal rays red to orange. 



