266 FISHES OF WESTERN SOUTH AMERICA 
342. APHYOCHARAX PUSILLUS Giinther 
Aphyocharax pusillus Ginther, 1868, Proc. Zool. Soc. London, 245, three specimens, 24 inches, 
Bartlett collection, Xeberos, Huallaga; 
Cope, 1872, Proc. Acad. Nat. Sci. Phila., XXIII, 260, Hauxwell collection, Rio Ambyiacu; 
Cope, 1878, Proc. Amer. Phil. Soc., XVII, 689, Orton collection, Rio Maranon; 
Fowler, 1906 (1907), Proc. Acad. Nat. Sci. Phila., LVIII, 333, fig. 22; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 429. 
The Maranon and its tributaries 
343. APHYOCHARAX FILIGERUS Cope 
Aphyocharax filigerus Cope, 1870, Proc. Amer. Phil. Soc., XI, 564, Pebas, Hauxwell collection; 
Fowler, 1906 (1907), Proc. Acad. Nat. Sci. Phila., LVIII, 334, fig. 23; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 429. 
The Peruvian Amazon 
344. APHYOCHARAX ALBURNUS (Giinther) 
Chirodon alburnus Giinther, 1869, Proe. Zool. Soc. London, 424, fig. 2, Rio Marafion, one specimen, 
23 inches. 
Aphyocharax alburnus Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, IIT, 429. 
Peruvian Amazon and La Plata basins 
Subfamily GASTEROPELECINAE 
Gasteropelecidae Jordan, Evermann, and Clark, 1928 (1930), Rept. U.S. Comm. Fish., Part I, 99. 
The flying powers of these fishes are the subject of a study by Ridewood (1913), 
in which he found the flying mechanism to surpass by far in its development and 
specialization that of Hxocoetus, a flying-fish. He seems to have demonstrated that 
there is an actual flight and that they maintain a much longer trajectory through the 
air than would be possible by planing. He shows further that the pectoral girdle 
is greatly expanded and the pectoral muscles enlarged in Thoracocharax to one- 
fourth the body weight, while in a nearby form they constitute only one-one-hun- 
dred-fortieth the total weight. 
Genus 133: GASTEROPELECUS Gronow 
Gasteropelecus Gronow, 1756, Mus. Ichth., H, 7; 
Gronow, 1763, Zoophyl., 135; 
Giinther, 1864, Cat. Fish. Brit. Mus., V, 342; 
Garman, 1890, Bull. Essex Inst., XXII, 8; 
‘igenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 489. 
Type: Clupea sternicla Linnaeus = Salmo gasteropelecus Pallas 
The Amazons 
Short, extravagantly compressed, and belly line deflected downward to near 
the origin of the anal; adipose fin present; premaxillary teeth in a single series; 1-3 
large, conical teeth along the margin of the manillary. 
