322 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 95 
Color, in alcohol, pale with a silvery band posteriorly, sometimes 
blackish, ending in a dark, caudal spot; margins of scales on back out- 
lined with black pigment cells; top of head behind orbits blackish; 
snout and tip of chin somewhat speckled with black pigment cells; 
small dark humeral spot more or less developed; peritoneum silvery 
with widely spaced black pigment cells; cheeks and isthmus silvery. 
Remarks.—This new species differs from all other characinids 
referred to the subfamily Cheirodontinae that have complete lateral 
lines and lack a saclike dermal organ, in the shape of its teeth, which 
are unlike in upper and lower jaws. It is nearest to the genus Holo- 
shesthes but differs in lacking teeth on the maxillary. 
Named geayi in honor of the French writer F. Geay, who in 1896-97 
reported on the fisheries of the Orinoco Basin in his work ‘‘Péches dans 
les Affluentes de l’Orinoque.”’ 
Genus GEPHYROCHARAX Eigenmann 
Gephyrocharax E1GENMANN, Indiana Univ. Bull., vol. 10, No. 8 (Indiana Univ. 
Stud. No. 16), p. 23, 1912. (Type, Gephyrocharax chocoensis Kigenmann.) 
The frontal fontanel was observed to be variously developed, be- 
coming reduced with increase in size. Its variance among the several 
species was too great to use it as a major character in the following 
key as was done by Higenmann and Myers (Mem. Mus. Comp. Zool., 
vol. 43, No. 5, p. 477, 1929): 
KEY TO THE SPECIES OF GEPHYROCHARAX 
la. Outer caudal rays black, this black pigment joining with black caudal spot; 
middle rays of caudal fin pale; a darkish humeral spot only slightly devel- 
oped; lower lip thin, not fleshy at symphysis (both slopes of Panama). 
Gephyrocharax atracaudatus Meek and Hildebrand 
1b. Outer caudal rays pale. 
2a. A dark spot at base of first dorsal rays; tips of pectorals usually black in 
males; a dark caudal spot and a dark humeral bar (Magdalena Basin, 
(Grol¥eveall ovis) MUN ew eS eA a Gephyrocharax melanocheir Higenmann 
2b. No black area at base of dorsal fin rays. 
3a. Black caudal spot, if present, not continuing as a black band or streak 
to end of middle caudal fin ray. 
4a. No humeral blackish bar or spot, a collection of dark chromatophores 
sometimes visible but never forming a distinct vertical bar or spot; 
the dark caudal spot more or less present, but when best developed 
not blackish; an underlaid silvery leaden axial streak, most distinct 
along side of tail. 
5a. Origin of dorsal an equal distance between base of caudal fin and 
opercle; caudal spot somewhat developed, darkish but fading on 
basal middle caudal fin rays; depth 3.4 to 4 (Rio Chapore, 
EXO) byt 29) Jo ate NEAL UR AN i Gephyrocharax chaporae Fowler 
5b. Origin of dorsal fin equidistant between base of caudal fin and rear of 
‘operculum to a half eye diameter behind head; no humeral spot; 
depth about 3.0 to 3.75. 
