100 
BULLETIN OF THE BUREAU OF FISHERIES 
C. nebulosus remains more slender than C. regalis (depth in standard length of 
the former 3.95 to 4.2 and the latter 3.3 to 3.5), the head is lower and more pointed, 
and the mouth is less strongly oblique (the gape in C. nebulosus being wholly below 
the eye, whereas in C. regalis it is only a little below the middle of the eye anteriorly). 
The caudal fin is rather short and only moderately pointed in C. nebulosus, the longest 
rays being about as long as the head, whereas in C. regalis the fin is long, sharply 
pointed, the longest rays being notably longer than the head. The differences in 
color remain about as indicated for specimens 16 to 20 millimeters long. 
Specimens 85 millimeters and upward in length . — The larger young of this species 
have been described adequately by Welsh and Breder (1923, pp. 164 to 169) and the 
descriptions by these authors were augmented with remarks on smaller fish by Pearson 
(1929, pp. 178 and 179). It does not appear essential, therefore, to draw up further 
descriptions. However, it does seem desirable, in the light of the study of large series 
of specimens, to include a discussion of the relationship of this species and C. regalis, 
as development proceeds. 
The species are most readily separated by color, as the patterns are very different. 
However, evident structural differences also are present. In C. nebulosus the dark 
longitudinal bands, present in smaller specimens, begin to break up into spots when 
the fish are about 30 millimeters long. At a length of 35 to 40 millimeters, the band 
on the back is divided into more or less definite quadrate blotches, but the lateral 
band remains almost continuous. When the fish reach a length of about 60 to 70 
millimeters the lateral band also becomes divided into spots, and the caudal fin, which 
previously was almost solidly black at the base, has become spotted. At about the 
same size spots develop between the bands, and at a length of 70 to 80 millimeters 
the entire upper half of the side bears indefinitely outlined spots, which are irregular 
in shape and variable in size. The spots (in preserved specimens) are rather more 
brownish in color than in younger fish. At a length of 110 to 120 millimeters, the 
characteristic small, roundish black spots of the adult, which occupy the upper 
two-thirds of the sides as well as the dorsal and caudal fins, are quite fully developed. 
Specimens of C. regalis, 35 to 40 millimeters long, on the other hand, have broad 
dark crossbands on the upper part of the side, which extend to or somewhat below 
the lateral line. These bars disappear when the fish reach a length of about 70 to 
80 millimeters. Specimens ranging from about 80 to 100 millimeters in length are 
almost plain grayish above and silvery below. The characteristic dark wavy lines 
