320 FISHES OF WESTERN SOUTH AMERICA 
444. STERNARCHORHAMPHUS MULLERI (Steindachner) 
Sternarchus (Rhamphosternarchus) miillerd Stemdachner, 1881 (1882), Denksch. Kix. Akad. Wiss. 
Wien, XLIV, 18, pl. xviu, fig. 4. 
Sternarchorhynchus miller? Eigenmann and Eigenmann, 1891, Proc. U.S. Nat. Mus., XIV, 62. 
Sternarchorhamphus millert Eigenmann and Ward, 1905, Proc. Wash. Acad. Sci., VII, 166; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 449; 
Ellis, 1913, Mem. Carnegie Mus., VI, 142, fig. 10; 
Fowler, 1939 (1940), Proc. Acad. Nat. Sei. Phila., XCI, 276, two, 358 and 400 mm., Con- 
tamana. 
From the Lower Amazon to the Ucayali 
Genus 178: APTERONOTUS Lacépéde 
Anteronotus Lacépede, 1800, Hist. Nat. Poiss., Il, 208, passan = albifrons; 
Jordan, 1917, The Genera of Fishes, Stanford Univ. Publ., Part I, 56. 
Sternarchus Bloch and Schneider, 1801, Syst. Ichth., 497, albifrons; 
Cuvier, 1817, Régne Anim., II, 237; 
Eigenmann and EKigenmann, 1891, Proc. U.S. Nat. Mus., XTV. 61; 
Figenmann and Ward, 1905, Proc. Wash. Acad. Sci., VII, 161; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 448: 
Higenmann, 1912, Mem. Carnegie Mus., V, 438; 
Ellis, 1913, Mem. Carnegie Mus., VI, 145. 
Type: Gymnotus albifrons Linnaeus 
Amazons, British Guiana to Paraguay and Rio Parana 
Fontanels present; caudal present, and small; both jaws with patches of teeth; 
mouth large, gape long and horizontal, lower jaw included within the upper, two 
or more rows of teeth in the upper, two rows on lower; snout short and not tubular; 
eyes without a free orbital margin; back scaled, head naked, scales cycloid; pectorals 
not equal to more than half the depth; origin of anal at or before vertical from gill. 
opening, of uniform depth, not reaching caudal. 
KEY TO THE SPECIES OF THE GENUS APTERONOTUS 
a. Seales small, 11 to 16 rows above the lateral line 
b. Snout more or less pointed, interorbital width more than 5 in the head 
c. Distance of eye to snout twice the distance from eye to upper angle of gill-opening 
as ess oa Des seats saw ccaBte nese athe NO Seas Secs RG Coa CAIN at hoi ee anas 
ce. Distance of eye to snout less than the distance of the eye to upper angle of the gill- 
OPENING: age atest wcroh eee ch iru < ererancea com arya: Cue et eet nner leptorhynchus 
bb. Snout blunt, interorbital width less than 4.75 in head 
d. Rather slim; flesh color to light grey, entirely covered with fine chromatophores 
BOR ie ek ae heron ee te Mees eee) Sie tS, re AONE a eres HONEA Rita & Go Wei os Gt hasemani 
dd. Robust; ground-color dead black; 2 white bands encircling body, one at base of 
caudal, the other near end of anal; frontal area more or less white. . . .albifrons 
aa. Scales above lateral line large, not to exceed eight rows.................0 0.000005 bonaparti 
445. APTERONOTUS ALBIFRONS (Linnaeus) 
Gymnotus albifrons Linnaeus, 1766, Syst. Nat., ed. xi, 428. 
Sternarchus albifrons Bloch and Schneider, 1801, Syst. Ichth., 497, pl. xciv; 
Castelnau, 1855, Anim. Amér. Sud, Poiss., 91, pl. xlv, fig. 1; 
Cope, 1878, Proc. Amer. Phil. Soe., XVII, 682, Peruvian Amazon; 
