268 FISHES OF WESTERN SOUTH AMERICA 
longer and wider; anal low, with elongated basis, 2.3 in standard length, and rays 
about 30; ventral fins wanting; pectorals for flying, long, sickle-like, tapering, 
curved both in horizontal and vertical planes, rays about 9, the first the longest, 
2.2—2.3 in body length. 
Flat, three-ridged contours of the head continue brokenly in three scale-series 
along the back, tapering caudally for five scale-rows; thence a single series of eleven 
median, saddle-like scales continue to the origin of the dorsal, uniformly narrowing 
to a sharper edge. Caudal peduncle low and compressed, delicate, slightly higher 
in its four scale-rows than the diameter of the orbit; four scales separate dorsal and 
adipose fins; fins not scaled except for a few on the base of the caudal, and two series 
on the base of the anal rays; scales cycloid, having one or two conspicuous radials. 
Lateral line pores about twelve, in a very direct line, deflected ventrally to a point 
four scales above the origin of the anal. More than thirty scales like ridge-tiles 
form the median series along the very sharp pre-ventral line. 
Anus notched into ventral contour three-tenths nearer caudal basis than to 
chin; post-anal trunk an acute angle, with its apex on the caudal peduncle, the angle 
approximately trisected by two lines, the first line being the widest part of the trunk 
along the middle of the vertebrae, the second line seen translucently along the 
border between haemal processes and the radials of the anal fin. Viscera seen 
darkly opaque, descending obliquely from opercle to vent; Just above and behind 
this the broad, translucent line of the air-bladder, bulbous anteriorly; ribs seen 
radiating through translucent breast. 
Iris and opercle yellow and iridescent; a black, longitudinal line, 33 scales long, 
half a scale wide, in the fourth series from the dorsal fin, from third or fourth row 
to the base of the middle caudal rays; a narrow, dark line parallels the edge of the 
venter to the end of the anal, brokenly on the anal basis; upper scales and proximal 
portion of caudal fin finely sprinkled with chromatophores; anal rays outlined finely 
in dark; pectorals with rows of chromatophores diminishing toward the last; first 
ray with rings of dots, segment-like in appearance; body color yellowish silvery. 
The allusion of the name is to the encirclement of the back by the pair of dark 
lines mentioned above. 
Genus 134: THORACOCHARAX Fowler 
Thoracocharax Fowler, 1906 (1907), Proc. Acad. Nat. Sei. Phila., LVIII, 452; 
Higenmann, 1910, Rept. Princeton Univ. Exped. Patagonia, III, 439. 
Type: Gasteropelecus stellatus Kner 
Pacific slope of Panama and Orinoco to the Paraguay 
Anterior profile of the back convex. 
347. THORACOCHARAX STELLATUS (Kner) 
Gasteropelecus stellatus Kner, 1860, Denksch. Kix. Akad. Wiss. Wien, XVIII, 17; 
Gill, 1870, Proce. Aead. Nat. Sci. Phila., XXII, 92, Marafion or Napo, Orton collection; 
Cope, 1870, Proc. Amer. Phil. Soc., XI, 566, Pebas, Hauxwell coll.; 
