FISHES OF MINNESOTA 53 



Family APHREDODERIDJE. The Pirate Perches. 



Body considerably compressed; back somewhat elevated; head 

 flattened above. Mouth of medium size, rather oblique, lower jaw 

 projecting beyond the upper. Jaws, vomer, palatines and ptery- 

 goids with teeth; upper jaw not protractile; maxillary bones well 

 developed; preopercle and preorbital with their edges toothed or 

 serrate; a spine on the opercle. No pseudobranchia; G branchios- 

 tegal rays; scales ctenoid, no lateral line. Vent in adult speci- 

 mens located just back of the lower jaw. Air-bladder simple; 

 pyloric cseca 12. 



Genus APHREDODERUS Le Sueur. 



Aphrecloderus sayanus (Gilliams). Pirate Perch. 



Color very dark, dotted with darker. Caudal fin with two black 

 bars at its base, a lighter bar between these. Body oblong, rather 

 heavy anteriorly, compressed posteriorly; back somewhat elevated 

 in the region of the dorsal fin. Dorsal fin rather high, its rays II, 

 6. Ventrals 7. Head contained 3 times in the length. Depth 3. 

 Scales ctenoid, varying from 45 to 60 in a direct line from the 

 opercle to the base of the caudal fin. Length 5 inches. 



The interesting point about this little fish is the location of its 

 vent, which in the young is situated in about the natural position, 

 but as the fish matures the vent gradually passes forward, and in 

 the adult it is located just back of the mouth. 



At present there is but one specimen recorded in the state, and 

 that is now in the museum of the Mankato State Normal School. 

 It was secured at Winona by Prof. J. M. Holzinger, where it is said 

 to be rare. The fishermen at Winona call it a black bass, but con- 

 sider it different from our common bass. 



Family ATHERINID^. The Silversides. 



Body enlongate, compressed; scales usually cycloid, but not in 

 our species, no lateral line; jaws, vomer and palatines set with 

 teeth. Upper jaw not protractile; gill membranes free from the 

 isthmus; pseudobranchia developed; gill rakers long and slender; 

 branchiostegal rays 5 or 6. Two dorsal fins, these far apart, the 

 first composed of 3 to 8 slender spines, the second of soft rays; 

 anal fin preceded by one spine; ventral rays I, 5, A well developed 

 air-bladder but no pyloric cajca. The family is represented in the 

 state by but one genus and one species. 



