66 
BULLETIN OF THE BUREAU OF FISHERIES 
They are almost colorless, having only a slight yellowish tinge, and they contain from 
1 to 18 oil globules. If only one globule is present! it is larger than if several are 
present. During the development of the egg the oil globules become amalgamated 
until only one remains at hatching. The incubation period has a duration of 46 to 
50 hours in water temperatures of 68° to 70° F. Segmentation and development 
proceeded as in Bairdiella (Kuntz, 1914). About 18 hours after fertilization grayish 
chromatophores appeared on the dorso-lateral aspects of the embryo and on the sur- 
face of the oil globule. Six hours later the chromatophores had become black on the 
oil globule, and the embryo was dotted with black. Some black chromatophores 
were scattered also over the yolk near the embryo. 
Newly hatched young . — The following account of the newly hatched young is 
based on descriptions and figures by Welsh and Breder (1923, pp. 190-193, figs. 50- 
53). The fry are 2.0 to 2.5 millimeters long at hatching, and they float in an inverted 
position. The head is slightly deflected, the vent is notably in advance of midbody 
length, and the oil globule lies in the posterior part of the yolk sac. Pigmentation 
consists of three vertical bands, each consisting of black and dull gold chromato- 
phores, the first one being above the vent and two posterior to it. A patch of 
chromatophores of the same colors lies in the dorsal finfold anteriorly, and similar 
ones are scattered over the yolk sac. 
None of the larvae lived over 7 days. They lost the gold pigment by the second 
day and all markings had become less conspicuous. By this time the pectoral fins 
had become plainly visible. On the fourth day only traces of dark bands remained, 
and a row of black chromatophores had appeared along the ventral surface posterior 
to the vent. The blotch in the dorsal finfold remained conspicuous, the eye had 
become pigmented, the pectoral fins had become dotted with black and gold chromato- 
phores, and the abdomen had a golden tinge. The yolk sac was almost completely 
absorbed, and the mouth was open. On the fifth day the larvae, when at rest, 
floated with the head downward. With the unaided eye the fry appeared dark 
brown anterior to the vent, and the tail was transparent. On the sixth day the eye 
had a steel-blue luster, and no trace of rudimentary fins was evident. On the seventh 
day, shortly before the longest survivors died, a few of the fry had attained a length 
of 2.8 millimeters. Therefore, very little growth had been gained. 
The larvae described by Welsh and Breder were preserved, in part, and were 
compared by us with the smallest fry of americanus taken at Beaufort. Although 
specimens of the last-mentioned species, quite as small as the larvae described in the 
preceding paragraphs, were taken at Beaufort, the resemblance is very remote, as 
stated elsewhere (p. 55), which apparently is caused partly by a difference in age 
and partly by the differences of the two species. 
The account of the development of this species must remain incomplete for the 
present, as the stages between the newly hatched young and specimens 10 millimeters 
in length have not been secured. 
Sjjecimens 10 millimeters long . — The body is rather deep, compressed, the greatest 
depth being contained about 2.8 to 2.9 in length to the base of caudal fin. The head 
is quite narrow, compressed, and its length is equal to or a little longer than the 
greatest depth of the body. The interorbital is convex. The eye is longer than the 
snout, and it has a very small vertically slightly elongate pupil. The mouth is large 
and moderately oblique, the upper lip anteriorly being nearly on a level with the 
lower margin of the pupil. The maxillary reaches somewhat past the middle of the 
eye, and the upper jaw projects beyond the lower one. The fins are all well developed, 
