1894.] Variation of North American Fishes. 641 
VARIATION OF NORTH AMERICAN FISHES.* 
E 
THE VARIATION OF ETHEOSTOMA CAPRODES 
RAFINESQUE. 
By W. J. MoENKHAUS. 
Etheostoma is a genus of American Freshwater Percide. It 
consists of about 100 species distributed in a number of sub- 
genera. All the members of the genus are small. They are 
distributed over approximately the entire Atlantic slope of 
North America. The northernmost points are Fort Quappelle 
and Montreal; the southernmost, Chihuahua. The most west 
ern points are Colorado and Swift Current in Canada near 
the 108th meridian. 
The subgenus Percina includes the largest of the darters. 
There are but two well-defined species. One, Etheostoma rex 
is known from east of the Alleghany Mountains. The other, 
Etheostoma caprodes is also found east of the Alleghanies, but 
its chief habitat is west of these mountains, where it is found 
from Lakes Champlain and Superior to the Rio Grande. 
This latter species, Etheostoma caprodes Rafinesque, has been 
studied with a view to ascertain the extent of its variation, the 
relation of its variation to its geographical distribution, the 
extent of variation in each locality, and the variation with 
age. This species of the darters has been selected for its size, 
and on account of its wide distribution and moderate abund- 
ance within its limits. Its variability has been known for a 
long time, and has given it a number of specific names. 
The material examined is recorded in the table of measure- 
ments and counts. 
The greatest variation was found to be in the color. Slighter 
variations were found in proportions and number of fin rays. 
* Contributions from the Zoological Laboratory of Indiana rins under ler 
the direction of Carl H. Eigenmann, No. 10. [OA 
