24 
06) 
FISHES OF WESTERN SOUTH AMERICA 
Colosoma (Waiteina) nigripinnis Fowler, 1906 (1907), Proc. Acad. Nat. Sci. Phila., LVIIT. 473, 
fig. 55, Peruvian Amazon. 
Piarctus nigripinnis Eigenmann, 1915, Ann. Carnegie Mus., TX, 262, pl. lin; 
Ahl, 1922, Blaett. Aquar-Terrarienkunde, no. 12, 1, fig. 
The Amazons 
15668, 4+, 158-227 mm., Iquitos, Allen, September, 1920. 
15669, 1, 150 mm., Yarinacocha, Allen, August, 1920. 
Anterior part of adipose with jointed rays; ‘‘inferior part’’ scaly; scales 26, 
65 + 6, 21. 
Genus 116: COLOSSOMA Eigenmann 
Colossoma Eigenmann, 1903, Smithson. Mise. Coll., XLV, 148; 
Eigenmann and Kennedy, 1903, Proc. Acad. Nat. Sei. Phila., LV, 530; 
Kigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, II, 444. 
Colosoma Eigenmann, 1915, Ann. Carnegie Mus., LX, 261, 262. 
Waiteina Fowler, 1906 (1907), Proc. Acad. Nat. Sci. Phila., LVIII, 473, for Myletes negripinnis Cope. 
Reganina Fowler, 1906 (1907), Proc. Acad. Nat. Sci. Phila., LVIIT, 475, for Myletes bidens Agassiz. 
Type: Myletes oculus Cope 
The Amazons and La Plata 
Predorsal spine wanting; mandibular teeth conical; teeth close-set and incisor- 
like, molar-like, or with oblique cutting edge; premaxillary with each ramus bearing 
an outer series of five and an inner series of two teeth; abdomen serrated both 
before and behind ventral fins. 
302. CoLOssoMA OcULUS (Cope) 
Myletes oculus Cope, 1871 (1872), Proc. Acad. Nat. Sci. Phila., XXIII, 268, pl. xii, fig. 2, Rio Am- 
byiacu, Hauxwell collection. 
Colossoma oculus Eigenmann, 1903, Smithson. Misc. Coll., XLV, 148; 
Fowler, 1906 (1907), Proc. Acad. Nat. Sci. Phila., LVIII, 472; 
Kigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, IIT, 444; 
Norman, 1928, Proc. Zool. Soc. London, 811. 
Peruvian Amazon 
Norman differentiates this species from his C. nigripinnis on larger head, 
fewer gill-rakers, unrayed adipose, and coloration, and considers it possibly the 
young of that species. 
303. COLOSSOMA BIDENS (Agassiz) 
Myletes bidens Agassiz, 1829, Sel. Gen. et Spec. Pisce. Bras., 75, pl. xxx; 
Giinther, 1864, Cat. Fish. Brit. Mus., V, 375; 
Cope, 1871 (1872), Proc. Acad. Nat. Sci. Phila., 291, Perkins coll.; 
Cope, 1878, Proce. Amer. Phil. Soe., XVII, 694, Maranon, Orton coll.; 
Steindachner, 1881 (1882), Denksch. KIx. Akad. Wiss. Wien, XLIV, 13. 
Reganina bidens Fowler, 1906 (1907), Proc. Acad. Nat. Sei. Phila., LVI, 475. 
