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BULLETIN OF THE BUREAU OF FISHERIES 
originating over seventh or eighth myomere, rather low and even to lophocercal tail, 
thence forward to yolk sac past vent, which ends at a distance from body at edge of 
fin fold; pectorals developed but small, unrayed, inconspicuous, held tightly against 
yolk sac. 
Pigmentation. — There are no dorsal or lateral chromatophores, but many large, 
black, stellate ones occur over ventral and lateral aspects of the yolk sac, and a row 
of 15 along ventral edge of myomeres from behind yolk sac to end of tail. 
6.0-millimeter stage (somewhat older than preceding).' — Total length, 6.0; length 
to vent, 3.0; greatest depth, 1.15; diameter of eye, 0.5 millimeters. Myomeres, 13 to 
Figure 77 . — Percopsis omiscomaycus, 7 millimeters 
vent plus 21 behind. Total length identical with the newly hatched specimen, but 
yolk sac greatly reduced and body much heavier behind vent; a single-chambered 
air bladder evident, covered with subsurface chromatophores. 
Pigmentation. — Essentially as before. 
7.0-millimeter stage . — Total length, 7.0; length to vent, 3.4; greatest depth, 1.1 
diameter of eye, 0.5 millimeter. Myomeres, 13 to vent plus 21 behind. Snout still 
somewhat decurved and mouth inferior; marginal fin unchanged; pectorals larger. 
Pigmentation. — The 7-millimeter specimen is characterized by a very few large 
stellate chromatophores situated in the antero-ventral part of stomach region, ex- 
tending up only on the right side. This unsymmetry is constant and apparently due 
to uneven development of this region. A ventral line of small chromatophores ex- 
tends backward from anus, and a subsurface group over the stomach constitutes the 
only other marking. 
9 .5 -millimeter stage . — Total length, 9.5; standard length, 8.1; length to vent, 5.0; 
greatest depth, 2.0; diameter of eye, 0.8 millimeter. Myomeres, 14 to vent plus 20 
behind. Characterized by long head with long, pointed snout; mouth moderate with 
delicate teeth in both jaws; body not compressed; air bladder large, one chambered. 
Eleven dorsal rays developed extending shortly beyond vent, and large portion of 
embryonic marginal fin fold persistent behind; anal incomplete with eight rays de- 
veloped, originating below and just before end of dorsal; ventrals apparent for first 
time, inserted below dorsal origin; caudal forked. Eye higher than in preceding 
stages. 
