Percoidea, or Perch-like Fishes 3 1 5 



the rainbow darter or soldier-fish, with alternate oblique bands 

 of blue and scarlet, is doubtless the most familiar of the bril- 

 liantly colored species, as it is the most abundant throughout 

 the Ohio valley. 



Etheostoma flabellare, the fan-tailed darter, discovered by 

 Rafinesque in Kentucky in 1817, was the first species of the series 

 made known to science. It has no bright colors, but its move- 

 ments in water are more active than any of the others, and it 

 is the most hardy in the aquarium. 



Psychromaster tuscumbia abounds in the great limestone 

 springs of northern Alabama, while Copelandellus quiescens 

 swarms in the black-water brooks which flow into the Dismal 

 Swamp and thence southward to the Suwanee. It is a little fish 

 not very active, its range going farther into the southern lowlands 

 than any other. Finally, Microperca punctulata, the least darter, 

 is the smallest of all, with fewest spines and dullest colors, must 

 specialized in the sense of being least primitive, but at the same 

 time the most degraded of all the darters. 



No fossil forms nearly allied to the darters are on record. 

 The nearest is perhaps Mioplosus labracoides from the Eocene at 

 Green River, Wyoming. This elongate fish, a foot long, has 

 the dorsal rays IX-i, 13, and the anal rays II, 13, its scales 

 finely serrated, and the preopercle coarsely serrated on the 

 lower limb only. This species, with its numerous congeners 

 from the Rocky Mountain Eocene, is nearer the true perch 

 than the darters. Several species related to Perca are also 

 recorded from the Eocene of England and Germany. A species 

 called Lucioperca skorpili, allied to Centropomus, is described from 

 the Oligocene of Bulgaria, besides several other forms imper- 

 fectly preserved, of still more doubtful affinities. 



