278 FISHES OF WESTERN SOUTH AMERICA 
Type: Plethodectes erythrurus Cope 
Range that of the one species 
Regan, 1912, justifies the abandonment of the genus on the ground that the 
teeth of the outer premaxillary series, while less expanded, are provided with a 
pair of cusps resembling C. macrolepidotus, but less expanded and somewhat more 
conical. Fowler still regards the genus as valid, in spite of Cope’s change of 
opinion. Jordan (1919) holds Plethodectes to be a synonym of Chalceus. 
365. PLETHODECTES ERYTHRURUS Cope 
Plethodectes erythrurus Cope, 1870, Proc. Amer. Phil. Soc., XI, 563, fig. 6, Pebas, Hauxwell col- 
lection; 
Fowler, 1906 (1907), Proce. Acad. Nat. Sci. Phila., LVIII, 441; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, IIT, 439. 
Chalceus erythrurus Cope, 1871 (1872), Proc. Acad. Nat. Sci. Phila., XXIII, 262, Rio Ambyiacu; 
Regan, 1912, Ann. Mag. Nat. Hist., (8), X, 388. 
Pebas, Peruvian Amazon, and Rio Cupai 
Genus 145: PIABUCINA Cuvier and Valenciennes 
Piabucina Cuvier and Valenciennes, 1848, Hist. Nat. Poiss., XXII, 161; 
Figenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 439; 
Kigenmann, 1922, Mem. Carnegie Mus., [X, 125. 
Type: Piabucina erythrinoides Cuvier and Valenciennes 
Panama to Ecuador and Guiana 
Similar to Lebiasina in the lack of fontanels, mandibular teeth in two series 
anteriorly, cellular anterior walls of air bladder; differing in that adipose fin is 
never wanting. 
366. PIABUCINA UNITAENIATA Gunther 
Piabucina unitaeniata Giinther, 1864, Cat. Fish. Brit. Mus., V, 311; 
Eigenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, IIT, 439. 
Canelos, Ecuador, to British Guiana 
367. PIABUCINA ELONGATA Boulenger 
Piabucina elongata Boulenger, 1887, Proc. Zool. Soc. London, 280, pl. xxiii, fig. 2, eastern Hcuador; 
Higenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 439. 
Piabucina unitaeniala Steindachner (non Giinther), 1882 (1883), Denksch. KIX. Akad. Wiss. Wien, 
XLVI, 41, Canelos, two specimens. 
Oriente of Ecuador 
Known from two specimens from Canelos and three from the Buckley collection 
taken at Sarayacu. 
