Jordan and Evermann. — Fishes of North America. 337 



141. BRYCON, Miiller «fe Troschel. 



Bryant, MCLLEBi Troschel, Hor.T^ Ichthyologiae, i, 15, 1845, (j'aicalus). 

 Chalcinopfit, KxEB, SitzuDprsber. Akail. Wiss. Miinchen, 1863, 226, '$triatuliu). 

 Megalobnjron, GiSTHEB, Proc. Zoijl. Soc. Lond., 1869, 423, (c^halus). 



Dorsal inserted behind ventrale, in middle of length of body; anal fin 

 long. Body oblong, covered with scales of uniform size ; belly rounded 

 before ventrals, compressed behind them. Mouth wide, the premaxillary 

 with 3 or 4 series of tricuspid teeth ; maxillary with small teeth ; mandible 

 with a series of strong tricuspid teeth and a pair of conical teeth in the 

 middle, behind them. Nostrils close together, separated by a valve. Gill 

 openings wide, the membranes slightly united, free from isthmus. Gill- 

 rakers lanceolate. Species numerous, chiefly Brazilian. {3pvKui, to bite.) 



CnALCisopsis, (Chalcinun, a related genus ; oi^i?, appearance): 

 a. Premaxillary teeth in four series. 



b. Scales moderate, 48 to 55 in lateral line. dejitex, 564. 



bh. Scales small, 73 to 80 in lateral line. STBiATUxrs, 565. 



Subgenus CHALCINOPSIS, Kner. 



.564. BBTCON DEXTEX, Gunther. 



Head 4^ ; depth 3^. D. 11 ; A. 35 ; scales 9-48 to 5.5-7. Snout longer 

 than eye in adult : maxillary not reaching to center of eye ; caudal deeply 

 forked ; pectoral reaching about to ventrals. Silvery, some scales spotted 

 or margined with black ; humeral part of gill opening black ; usually a 

 black spot at base of caudal ; anal usually black-edged. Yucatan to 

 Ecuador. (Giinther. ) (deiitex, large-toothed.) 



Brycon deniex, GCxtheb, Proc. Zool. Soc. London, 1860, 240, Esmeraldas, Ecuador. (Coll. 



Fraser.) 

 Chalcinopsis dentex, GCstheb, Cat., v, 337, 1864. 



565. BBTCOS STBIAirLUS (Kner). 



D. 11 : A. 36 or 37 ; scales 13-73 to 80-9. Scales much smaller than in 

 B. dentex : sides of body immaculate, or with rows of oblique brownish 

 spots ; caudal spot sometimes present. Eio Chagres and streams about 

 Panama. (Kner.) {striatulus, narrowly streaked.) 



Chiilcitiopsis striabtlus, KsEB, Sitzungsber. Akad. Wiss. Miinchen, 1863, 223, Panama ; GI'xtheb, 



Cat., V, 337, 1864. 

 Oiulcinopsis chaijresetisis, Knee, 1. c, 223, Rio Chagres ; Gi^xtheb, 1. c, 338, 1864. 



142. GASTEROPELECUS (Gronow; Pallas. 



Gaileropelecus, Gbonow, Mas. Ichthyol., 11, 7, 1763, (nonbinomial). 

 Gasteropelecus, Palias, Spicilegia, 1769, vnr, 50, {steniicla). 



Body strongly compressed, the thoracic region dilated into a semicir- 

 cular disk; the belly compressed to a sharp edge : scales moderate : lateral 

 line incomplete, descending backwards towards anal fin. Mouth 

 moderate, with compressed tricuspid teeth in 1 or 2 series in pre- 

 maxillary, in 1 series in lower jaw ; maxillary with a few minute conical 

 teeth ; palate toothless ; nostrils close together. Gill openings wide, the 



F. X. A. 23 



