230 FISHES OF WESTERN SOUTH AMERICA 
Figenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, IIT, 436; 
Eigenmann, 1918, Mem. Mus. Comp. Zool., XLII, ii, 163, pl. xx, fig. 2; pl. Ixxviii, fig. 1. 
Amazons 
268. HeMIGRAMMUS PAIPAYENSIS Pearson 
Hemigrammus paipayensis Pearson, in Eigenmann and Myers, 1929, Mem. Mus. Comp. Zool., 
XLII, suppl., 533, upper Maranon; 
Pearson, 1937a, Proc. Cal. Acad. Sei., (4), XXIII, 91. 
Upper Maranon basin 
A border species lying between Hemigrammus or Bryconamericus on the one 
hand and Knodus on the other, having characters pertaining to all three, in some 
individuals irregular. Myers in a footnote, page 534, throws doubt upon its being 
a Hemigrammus species. Dr. Pearson points out that the scales are larger than 
usual in the above group of genera; the second suborbital in contact with the pre- 
opercle below; the lateral line may be considered complete, and if so, and the caudal 
sealed, it is a Hemigrammus. 
269. HeMIGRAMMUS PULCHER Ladiges 
Hemigrammus pulcher Ladiges, 1938, Zool. Anz., CXXIV, 49. 
Peruvian Amazon 
Genus 104: HYPHESSOBRYCON Durbin 
Hyphessobrycon Durbin, 1908, Bull. Mus. Comp. Zool., LIT, 100; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, IIT, 436; 
Bigenmann, 1912, Mem. Carnegie Mus., V, 338; 
Eigenmann, 1918, Mem. Mus. Comp. Zool., XLII, i, 172. 
Type: Hemigrammus compressus Meek 
Mexico to Paraguay and Rio Sao Francisco 
Separated from Hemigrammus on the lack of caudal scales. 
270. HyPHESSOBRYCON SP. 
15914, 9, 34-44 mm., Moyobamba, W. H. Osgood, July, 1912. 
271. HypHESSOBRYCON ROBUSTULUS (Cope) 
Hemigrammus robustulus Cope, 1870, Proc. Amer. Phil. Soc., XI, 561, Pebas, Hauxwell collection ; 
Cope, 1878, Proc. Amer. Phil. Soc., XVII, 690, Peruvian Amazon, the Orton Collection ; 
Fowler, 1906 (1907), Proc. Acad. Nat. Sei. Phila., LVIII, 335, fig. 24, Pebas and Rio Maranon. 
Tetragonopterus robustulus Kigenmann and Higenmann, 1891, Proc. U.S. Nat. Mus., XIV, 54. 
Hyphessobrycon robustulus Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, ITT, 437; 
Figenmann, 1918, Mem. Mus. Comp. Zool., XLIII, ii, 195. 
Peruvian Amazonia 
