Percoidea, or Perch-like Fishes 295 
tion of the vent. In the adult this is in front of the ventrai 
fins, at the throat. In the young it is behind the ventral fins 
Fic. 228.—Pirate Perch, Aphredoderus sayanus (Gilliams). Illinois River. 
as in ordinary fishes. With age it moves forward by the pro- 
longation of the horizontal part of the intestine or rectum: 
The same peculiar position of the vent is found in the berycoid 
genus Paratrachichthys. 
In the family Aphredoderide but one species is known, 
Aphredoderus sayanus, the pirate-perch. It reaches a length 
Fic 229—Everglade Pigmy Perch, Elassoma evergladei Jordan. Jverglades of 
Florida 
we 
of five inches and lives in sluggish lowland streams with muddy 
bottom from New Jersey and Minnesota to Louisiana. It is 
