Percoidea, or Perch-like Fishes 511 
dull green in color and feeds on insects and worms. It has no 
economic value, although extremely interesting in its anatomy 
and relationship. 
Whether the Asineopide, fresh-water fishes of the American 
Eocene, and the Erismatopteride, of the same deposits (see page 
450) are related to A phredoderus or to Percopsis is still uncertain. 
The Pigmy Sunfishes: Elassomide.—One of the most primitive 
groups is that of Elassomide, or pigmy sunfiches. These are 
Fie. 399.—Skull of the Rock Bass, Ambloplites rupestris. 
very small fishes, less than two inches long, living in the swamps 
of the South, resembling the sunfishes, but with the number of 
dorsal spines reduced to from three to five. Elassoma zonatum 
occurs from southern Illinois to Louisiana. Elassoma ever- 
gladet abounds in the Everglades of Florida. In both the body 
