326 MEMOIRS OF THE CARNEGIE MUSEUM 



No humeral spot ; caudal with a small, diffuse, dark spot at the base of the middle 

 rays. Scales of sides margined with dark, the marginal s]iots tending to form dark 

 lines along the sides; pigment more profuse toward the l)ack; a scries of dark spots 

 on the median series of scales of the back. 



This species is named for Mr. S. E. Shideler, volunteer assistant on the Guiana 

 Expedition. 



182. Moenkhausia dichroura (Kner). 



Tetragonopterus dichrourus Kner, "Familie der Characinen," i, 1859, 41, pi. 9, 

 fig. 21 (Rio Guapore; Caigara; Paraguay). — GDnther, Catalogue, V, 18G4, 

 324.— EiGENMANN and Eigenmann, Proc. U. S. Nat. Mus., XIV, 1891, 53.— 

 Ulrey, Ann. N. Y. Acad. Sci., VIII, 1895, 279.— Perugia, Ann. Mus. 

 Genova, (2a), X, 1891, 45 (Chaco Centrale). — Boulenger, Trans. Zool. Soc. 

 London, XIV, 1896, 35 (San Luis and Descalvados). — Eigenmann and Ken- 

 nedy, Proc. Acad. Nat. Sci. Phila., 1903, 52 (Asuncion). 



Moenkhausia dichrourus Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 

 1910, 438.— Eigenmann and Ward, Ann. Carn. Mus., IV, 1907, 138, PI. XLI, 

 fig. 1 (Gorumba, Porto Max; Asuncion). 

 Two specimens, 59-62 mm. Warraputa Cataract. (C. M. Cat. No. 1345a; 



I. U. Cat. No. 11861.) 



Two specimens, 28-65 mm. Crab Falls. (C. M. Cat. No. 1346fl.) 

 Twelve specimens, 58-63 mm. Konawaruk. (C. M. Cat. No. 1347a-d; 



I. U. Cat. No. 11862.) 



Head about 4; depth usually 3; D. 11; A. 25-28; scales 5 or 5.5-34 to 39-3 



or 3.5; eye 2.4-2.6; interorbital slightly less than eye. 



The silvery lateral band is underlaid with a black band of the same size and 



shape. Base of caudal lobes in life bright yellow; middle caudal rays and a bar 



across the lobes black; tips of caudal lobes milk-white. 



183. Moenkhausia lepidura (Kner). 



Tetragonopterus lepidurus Kner, "Familie der Characinen," i, 1859, 40, pi. 8, 

 fig. 20 (Rio Guapore). — Gijnther, Catalogue, V, 1864, 328. — Steindachner, 

 "Flussfische Siidamerika's, " iv, 1882, 32 (Tabatinga; Cudajas; Obidos; Villa 

 Bella). — Eigenmann and Eigenmann, Proc. U. S. Nat. Mus., XIV, 1891, 

 53.— Ulrey, Ann. N. Y. Acad. Sci., VIII, 1895, 278.— Vaillant, Bull. Mus. 

 d'Hist. Nat., V, 1899, 155 (Carnot). 



Moenkhausia lepidurus Eigenmann, Repts. Princeton Univ. Exp. Patagonia, III, 

 1910, 438. 



