EIGENMANN: the freshwater fishes of BRITISH GUIANA 469 



Macrodon Schinz. 

 Macrodon Schinz, Das Thierreich, II, 1822, 482, revived by Gill, Proc. U. S. Nat. 



Mus., XXVI, 1903, 1015 (ancylodon) . 

 Ancylodon {ex Oken) Cuvier, Isis, 1817, 1182 (jaucUdens = ancylodon), not 



Ancylodon lUiger, 1811, a genus of mammals. 

 Sagenichthys Berg, An. Mus. Nac. Buenos Aires, 1895, 52 (ancylodon). 



The distinguishing characters of this genus are given in the key. It is repre- 

 sented in British Guiana by the single species : 



316. Macrodon ancylodon (Bloch and Schneider). 



Lonchurus ancylodon Bloch and Schneider, Syst. Ichth., 1801, 102 (Surinam). 



Ancylodon ancylodon Cuvier and Valenciennes, Hist. Nat. Poiss., V, 1830, 81 

 (Cayenne). — GiJNTHER, Catalogue, II, 1860, 311 (Surinam; West Indies). — 

 Jordan and Eigenmann, Rept. U. S. Fish Com. for 1886, 1889, 373 (Rio 

 Grande do Sul).— Vaillant, Notes Leyden Mus., XX, 1898, 17 (Guyane). 



Sagenichthys ancylodon Berg, An. Mus. Nac. Buenos Aires, IV, 1895, 52 (Mar del 

 Plata Montevideo, Maldonado). — Jordan and Evermann, Rept. U. S. Fish 

 Com. for 1895, 1896, 395. — von Ihering, "Os peixes da Costa do Mar no 

 Estado do Rio Grande do Sul," 1896, 13 (Sao Paulo). — Jordan and Evermann, 

 Bull. U. S. Nat. Mus. No. 47, II, 1898, 1416 (Rio Grande do Sul).— Har- 

 GREAVES, Fishes of Brit. Guiana, Appendix, 1904, 1. 



Macrodon ancylodon Schinz, Das Thierreich, II, 1822, 482. — Evermann and 

 Kendall, Proc. U. S. Nat. Mus., XXXI, 1903, 1015 (Argentina).— Gill, 

 Proc. U. S. Nat. Mus., XXVI, 1903, 1015. 



Ancylodon jaculidens Cuvier and Valenciennes, Hist. Nat. Poiss., V, 1830, 81 

 (Cayenne). — MIjller and Troschel, in Schomburgk, Reisen, III, 1848, 621. 

 — GtJNTHER, Catalogue, II, 1860, 311 (Surinam; West Indies). — Jordan and 

 Gilbert, Bull. U. S. Fish Com., II, 1882, HI (Panama). — Pellegrin, 

 Revue Coloniale, 1908, 590 (Guiane francaise). 



Ancylodon airicauda Gijnther, Rept. Challenger Exp., Zoology, I, vi, 1880, 12 

 (mouth of Rio de la Plata). 

 Seven specimens, 195-270 mm. Georgetown market. (C. M. Cat. No. 



2484a-d; I. U. Cat. No. 12577.) 



Two specimens, young (?), 67 and 86 mm. Georgetown market. (C. M. Cat. 



No. 2485a; I. U. Cat. No. 12578.) 



Head 3-3.25; depth 4; D. IX-I,27-29; A. 11,9 or 10; scales "75 with pores 



85 series"; eye 5.5-6.5 in the head; interorbital flattish, a little wider than the 



eye, 5 in the head. 



