76 
BULLETIN OF THE BUREAU OF FISHERIES 
generally referred to a different species, even by investigators who dealt with the large 
numbers of individuals handled by fishermen. The Atlantic and Gulf forms, then, 
apparently are separable when taken in bulk, but when we consider each character 
separately the matter is not so simple because usually there is considerable inter- 
gradation. However, when all the characters are considered together it becomes 
evident that the two fish are sufficiently different to be regarded as distinct species. 
The more striking differentiating characters are as follows: 
Color . — Apparently color was the chief character on which the distinction 
rested heretofore. The difference in adult fish is quite striking. The Atlantic coast 
fish usually has small spots arranged in rather indefinite and irregular streaks, while 
TOTAL NUMBER OF GILL RAKERS 
Figxjrp; 1 .— Frequency distribution of the total number of gill rakers on the first gill arch of 
Cynoscion arenarius and C. regalis. The solid columns represent specimens from the Gulf of 
Mexico ( arenarius ) and the blank columns species from the Atlantic coast (regalis), in this as 
well as in the subsequent figures. The numbers at the top of the columns represent the actual 
number of specimens studied 
the Gulf fish is usually pale. There is considerable variation in color. Occasionally 
there are Atlantic specimens that have the typical coloration faintly developed, 
while in some Gulf fish there may be faint development of pigmentation. However, 
taken as a whole, the adults of these two species may be separated nearly always by 
color alone, especially when in fresh condition. The young of both species are pale 
and hence can not be separated by color. 
Form of the caudal fin . — As in many other scisenids, the caudal fin of the young 
of Cynoscion is very pointed, the middle rays being considerably prolonged As the 
fish grow older the decided prolongation 6f the middle rays diminishes and the 
caudal fin becomes somewhat double concave. In regalis the transformation of the 
caudal fin is carried farther, and it becomes distinctly emarginate in large individuals. 
As may be expected in a case of this kind, there is considerable individual difference 
