1894.] Variation of North American Fishes. 643 
Around the eyes are seen faint indications of three bars: one 
extending forward ; the second downward, and the third back- 
ward (fig. 2). 
Comparing this pattern with the one in the young, we find 
that the whole bars are homologous in the two, and that the 
half bars have been added. 
A step in advance is taken by the adult specimens from 
Chocola Cr., Ala., fig. 3 (Nos. 76-82). These have the bars 
alternately long and short along the entire length of the body. 
The bars are considerably broader and more intense, and the 
whole bars have their ventral extremities much broadened, so 
as to form quite an apparent series of spots along the side. 
An additional half bar is added by the union of the spot 
above and the spot justin front of the black caudal spot. Here 
the three bars radiating from the eye are somewhat more dis- 
tinct than in the pattern already described. | 
The next series of individuals are Nos. 45-55, 72, 73 and 
75, in the list given below, and are represented by fig. 4. They 
are found in the Green, Cumberland, Tennessee and Arkansas 
River Basins. The color pattern here shows a greater irregu- 
larity in its bars, and has developed in addition a still shorter 
between each of the whole and half bars of the preceding 
pattern, so that we have now whole, half and quarter bars. 
'The series of lateralspots is present only along a part of the 
body. The bar extending anteriorly from the eye is broken 
into two shorter and less distinct ones. 
Of considerable significance in the specimen figured in fig. 
3 is the fact that in the bar between the dorsals, we have a 
notch indicating that some of the color-cells are separating 
from the whole bar. A similar condition is shown in thesame 
region of fig. 4. The quarter bars are apparently split off 
from the other bars. It is of interest that variations in the 
direction of an increased number of bars is always, as far as 
my specimens go, introduced at this point. Specimens inter- 
mediate between this and the preceding form show that the 
quarter bars always make their first appearance between the 
seventh and eighth whole bars and the included half bar. - 
