72 
BULLETIN OF THE BUREAU OF FISHERIES 
upper jaw projects beyond the lower one. The fins are all well developed and an 
accurate enumeration of the rays is obtainable. The longest spines in the first 
dorsal reach somewhat beyond the origin of the second dorsal when deflexed; the 
caudal fin is asymmetrically rounded, the longest rays being in the lower half of the 
fin ; the ventral and pectoral fins are rather long and co terminal, not quite reaching the 
vent. The body is densely dotted with dark chromatophores, pigmentation in some 
specimens being almost general, and dark brown in color as seen with the unaided 
eye. The spinous dorsal, the ventrals, and the pectorals are colorless. The caudal 
fin, too, is colorless or at most with one to a few dark dots on the base. The posterior 
half of the base of the soft dorsal and most of the base of the anal are black, the 
amount of black present varying among specimens, the rest of these fins being plain 
colorless (fig. 15). 
All specimens at hand of the size described were taken among black, partly 
suspended vegetable debris, which they resemble in color. Somewhat larger speci- 
mens caught in the same environment, too, are black, while specimens taken on white 
sand are pale silvery. It seems probable, therefore, that small fish, if caught in a 
different environment, too, would be paler in color. 
This species is recognized, when about 10 millimeters long, chiefly by the slender 
body; the broad head, which is somewhat quadrate in cross section; the small elliptical 
pupil; the broad asymmetrically rounded caudal; and by the absence of black on the 
spinous dorsal and ventral fins. 
The smallest specimen of this species at hand is 9 millimeters long. It does 
not differ noticeably from the 10-millimeter ones described in the foregoing para- 
graphs. It is quite unlikely that a confusion of this species has taken place with the 
smaller specimens of the genus identified and described as americanus. The 
very evident differences, existing at a length of 10 millimeters, as shown by 
the descriptions and illustrations offered, surely would be evident also in part in 
smaller specimens. 
Specimens 13 to 15 millimeters long . — The body has become rather deeper and 
heavier posteriorly, although the length and the greatest depth remain proportionately 
about the same as in 10-millimeter fish. The head is more compressed and less 
evidently quadrate in cross section. The mouth is only slightly oblique, and the 
snout projects somewhat beyond the upper jaw. No pronounced changes in the fin s 
have taken place. The caudal fin apparently has become slightly more pointed, but 
retains an asymmetrical shape. The body in the specimens at hand remains dark 
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