THE AMERICAN TETRAGONOPTERINAE. 127 
Vertebrae 11 +19. Six ray-bearing interhaemals in front of the first 
fully developed haemal spine, five between it and the second. 
Second air-bladder more or less boot-shaped, the “toe” and “leg” of the 
same length, the toe sharply bent down, its tip reaching about halfway between 
the spinal column and anal, its greatest diameter half the length of the head; 
anterior air-bladder equal to the length of the “leg” of the posterior. 
Alimentary canal about equal to the length without the caudal. 
2. GYMNOCORYMBUS TERNETZI (Boulenger). 
Plate 11, fig. 1. 
Tetragonopterus ternetzi BOULENGER, Proce. Zool. soc. Lond., 1895, p. 528; Trans. Zool. soc. Lond., 1896, 
14, p. 35, pl. 8, fig. 2 (Descalvados; Matto Grosso); Boll. Mus. univ. Torino, 1900, 15, no. 370, 
p. 2 (Urucum). 
Gymnocorymbus ternetzi EIGENMANN, Rept. Princeton univ. exped. Patagonia, 1910, 3, p. 137. 
Hasirat.— Paraguay and Guaporé Basins. 
Specimens examined. 
Number of 
Catalogue number specimens Size in mm. Locality Collector 
11435 I. Cotype 1 39 to base Descalvados Ternetz 
ot caudal) 
3294 C. 4 39-53 Arequa, Paraguay Haseman 
3295 C. 12 38-54 Jauru, Paraguay Basin Haseman 
3296 C. 1 Bi San Joaquin, Guaporé Haseman 
Basin 
Very close to G. thayert. 
Head 3.25; depth 1.8; D. 11 or 12; A. 40-42; scales 8-30 to 35-8; eye 
2.5 mm.; interorbital 2.5. 
Parietal portion of the posterior fontanel not demarked from the groove 
on the occipital process; a single maxillary tooth. 
Gill-rakers 9 + 14. 
Anal sheath of five or six rows of scales covering half of the anal. 
About ten striae on a scale above the middle of the lateral line. 
Origin of dorsal equidistant from tip of snout and end of adipose fin or 
nearer caudal than snout; origin of anal and base of fourth dorsal ray equi- 
distant from tip of snout; margin of anal rounded; origin of ventrals and 
fourth scale in front of dorsal equidistant from tip of snout, reaching anal. 
The vertical bars more uniform in color throughout their height than in 
G. thayeri, separated by a wider interspace, the second bar largely behind origin 
of dorsal; anal and area above it, with the caudal peduncle dark; dorsal, dark. 
