246 FISHES OF WESTERN SOUTH AMERICA 
Subfamily: MYLINAE 
Resembling the Serrasalmoninae closely in the great depth, the compressed 
form, and serrated ventral line. 
Mandible with a single series of teeth, and in some cases a pair of subconical 
teeth behind those of the symphysis and in contact with them; palate and mawil- 
lary edentulous; dorsal fin rather long, ventrals very small; anal long, oblique; adi- 
pose variable; gill-rakers well developed. 
Genus 113: METYNNIS Cope 
Metynnis Cope, 1878, Proc. Amer. Phil. Soc., XVIT, 693; 
HKigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 443; 
‘igenmann, 1912, Mem. Carnegie Mus., V, 389; 
Kigenmann, 1915, Ann. Carnegie Mus., LX, 261, 267; 
Ahl, 1923, Mitt. Zool. Mus. Berlin, XI, 15; 
Norman, 1928, Proc. Zool. Soe. London, 815. 
Sealeina Fowler, 1906 (1907), Proc. Acad. Nat. Sci. Phila., LVIII, 478. 
Type: Metynnis luna Cope 
Guianas to Peru and Paraguay basin 
Belly trenchant and with a serrate median series of scales; premaxillary with 
two series of teeth; mandible with a pair of teeth behind the front series; a pro- 
cumbent, predorsal spine present; adipose exceeding half the length of the dorsal; 
free margin of anal slightly convex, lobate anteriorly, or sinuate; dorsal falcate, with 
fewer than 20 rays. 
298. METYNNIS LUNA Cope 
Metynnis luna Cope, 1878, Proc. Amer. Phil. Soc., XVII, 692, Peruvian Amazon; 
Fowler, 1906 (1907), Proc. Acad. Nat. Sci. Phila., LVII, 479, fig. 58, Orton collection of Cope; 
Figenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, IIT, 443; 
Ahl, 1923, Mitt. Zool. Mus. Berlin, XI, 20; 
Norman, 1928, Proc. Zool. Soc. London, 816, one, Amazon. 
Myletes hypsauchen Ulrey, 1895, Ann. N. Y. Acad. Sei., VIIT, 299. 
Maranon basin 
15610, 6, 68-98 mm., Lago Sanango, Allen, November, 1920. 
15698, 1, 33 mm., Lago Cashiboya, Allen, August, 1920. 
15802, 4, 62-68 mm., Yarinacocha, Allen, August, 1920. 
299. MeryNNIS HYPSAUCHEN (Miller and Troschel) 
Myletes hypsauchen Miller and Troschel, 1845, Horae Ichth., I, 38, pl. x, fig. 1; 
Cuvier and Valenciennes, 1848, Hist. Nat. Poiss., X XII, 219; 
Ginther, 1864, Cat. Fish. Brit. Mus., V, 376; 
Steindachner, 1882 (1883), Denksch. KK. Akad. Wiss. Wien, XLVI, 16, Rio Huallaga, one 
specimen. 
Metynnis hypsauchen Cope, 1878, Proc. Amer. Phil. Soc., XVII, 691; 
. Eigenmann and Eigenmann, 1891, Proc. U. 8S. Nat. Mus., XIV, 61; 
<< EKigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, IIT, 443; 
