ANNOTATED LIST OF THE SPECIES 225 
Atlantic and Pacific drainage of Colombia to Maranon 
Many specimens taken at Tingo de Pauca (upper Maranon) and the tributary 
Rio Crisnejas, down to Balsas. Close to B. peruanus of the western slopes of Peru 
and Ecuador, separated in space by the lowest passes of the middle Andes. 
259. BRYCONAMERICUS OSGoopI Eigenmann and Allen, sp. nov. 
Plate XIV, fig. 6 
15915, 1, 61 mm. to end of middle caudal rays, Moyobamba, W. H. Osgood, July, 1912. 
Near B. alpha, beta, and caucanus, having seven scales where they have six. 
Head 4.33; depth 2.5; D. 10; A. 28-29; eye more than 3; interorbital 3; scales 
7; 39; 5.5 or 6.5; erect, depth 2.7 in length without the caudal; compressed; dorsal 
and ventral contours convex, the ventral the deeper; slight depression above the 
occipital; elongate caudally, depth of peduncle 1.3 in its length. 
Maxillary teeth 4; premaxillary 4-4; manillary bone nearly equal to eye. 
Anal fin broad, its rays short, its base 3.4 in length of fish; origin of dorsal 
equidistant from snout and base of caudal, in front of anal, its first ray equal to 
head; pectoral triangular, its first ray nearly equal to first dorsal ray, and reaching 
to end of first third of ventral; ventrals small, only slightly longer than their dis- 
tance from the origin of the anal; caudal forked deeply, the ventral lobe slightly 
longer. 
Lateral line shghtly decurved; scales cycloid and very regular, even over the 
rounded preventral and predorsal ridges; sheath over base of cephalic half of anal fin. 
Colors obscured and not well preserved; a small dusky area across nape, another 
four scale-rows wide obliquely upward from distal end of pectoral; a third about four 
rows wide from base of dorsal to base of anal; and a fourth band from middle of 
anal upward. A dusky spot at upper ends of first 3 dorsal rays; pectoral and ven- 
trals apparently uniformly dark; anterior half of anal with longer rays and darker; 
middle caudal rays and nodes dark. 
To W. H. Osgood, who collected the type. 
260. BRYCONAMERICUS ALFREDAE Eigenmann 
Bryconamericus alfredae Pearson, 1924, Ind. Univ. Studies, no. 64, 43 (nom. nud.); 
Eigenmann, 1927, Mem. Mus. Comp. Zool., XLII, iv, 394, pl. xeix, fig. 1; 
Pearson, 1937a, Proc. Cal. Acad. Sci., (4), X XIII, 91, Rio Crisnejas. 
Upper Maranon to Urubamba and Beni basins 
“Tt is possible that this is the young of Acrobrycon ipanquianus, which is known 
from specimens twice as long as the largest of these.”’ Larger specimens have about 
12 weak teeth, conical or tricuspid, along the greater part of the maxillary border; 
in the young the more distal teeth are wanting. A. ipanqwianus has 8-9 maxil- 
laries. 
Genus 99: BRYCONACIDNUS Myers 
Bryconacidnus Myers, in Eigenmann and Myers, 1929, Mem. Mus. Comp. Zool., XLIII, v, suppl., 
545. 
