GILBERT: FISHES OF THE SUBGENUS LUXILUS


Codoma eurystoma Jordan and Brayton, 1878: 42, 84-85 (partim, type series con-
 tained specimens of N. zonistius and C. eurystoma [= N. venustus].
Luxilus zonistius Jordan, 1880:239-240 (original description; type series consists
 of young specimens forming part of Jordan and Brayton's type series of
 Codoma eurystoma; holotype USNM 23452, 68.5 SL; type locality Su-
 wannee Creek, Gwinnett County, Georgia).
 Minnilus zonistius, Jordan and Gilbert, 1883: 188-189 (description; range).
 Notropis zonistius, Jordan, 1885b: 814 (list; range).
 Coccotis zonistius, Jordan, Evermann and Clark, 1930: 128 (reference to orig-
 inal description; range).
 Hydrophlox zonistius, Schrenkeisen, 1938: 127 (characters; related to Hydro-
 phlox coccogenis; northern Georgia).
 DIAGNOSIS. A deep, compressed, small species of Luxilus, the
males rarely exceeding 85 mm SL. Notropis zonistius differs from
other members of its subgenus, except N. coccogenis, in the following
characters: 2 to 3 rows of weakly-developed nuptial tubercles on lower
jaw, extending to tip of chin (figure 14B); dorso-lateral scales outlined
with dark pigment; peritoneum speckled with dark pigment, not ap-
pearing uniformly black. N. zonistius is unique among forms of
Luxilus in having: dorsal fin with a strongly oblique black band
(orange-red in younger specimens) beginning on lower third of an-
terior margin and terminating at middle of posterior margin; a distinct
caudal spot, about equal to diameter of eye; a faint red bar along
cheek.
 N. zonistius and N. coccogenis are compared in table 1.
 DESCRIPTION. Fin ray and scale row counts and proportional
measurements are listed in tables 4 and 9 to 15. Characters men-
tioned in the diagnosis are not repeated in the following description:
 Body deep and compressed; mouth large, terminal, and oblique,
usually forming an angle of 570 to 610 with top of head (range 510
to 61.50); anterior dorso-lateral scales 15 to 18 (19); circumferential
scales (25) 27 to 30 (relative distribution of circumferential scales
usually 15 or 16-2-11 or 12; range 13-2-10 to 16-2-13); sum of anterior
dorso-lateral and circumferential scales (40) 43 to 48 (49); caudal ped-
uncle scales 13 to 15, usually 14; anal rays (8) 9 or 10, usually 9;
pectoral rays 14 to 16, usually 15; vertebrae 38 to 40, usually 39; color
of body olivaceous to steel-blue above; side of body with consider-
able coppery luster; pockets of some scales along side of body with
dark pigment, forming a few vertical crescent-shaped bars; prominent
gray-blue mid-dorsal stripe; tubercles on upper part of head best
developed on side and tip of snout, granular on top of head, back,
anterior part of dorsal fin, and upper surface of pectoral fin; tubercles
present on posterior edges of scales on upper half of body.


1964