FISHES 113 



2. Labidesthes Cope. Similar to Menidia but with the jaws pro- 

 duced to form a short beak: i species. 



L. sicculus (Cope). Brook silversides (Fig. 49). Length 85 mm.; 

 head 4.5; depth 6 to 8; color pale olive green with a distinct lateral 

 silvery band; back dotted with black; rays of dorsal fins IV-I, 9 to 11; 

 anal I, 23; scales 14-75; body very slender: western New York and the 

 Great Lakes to Iowa; southward to Florida and Texas; locally common 

 in ponds and sluggish streams. 



Suborder 4. Percoidei. — Body covered in most cases with ctenoid 

 scales; head usually with scaly cheeks and opercles; mouth mostly ter- 

 minal; pseudobranchiae usually well developed; dorsal fin made up of 2 

 portions, a spinous anterior and a soft-rayed posterior portion, which 

 may either be confluent or separate; anal fin usually with i to 3 spines; 

 ventral fins thoracic, with usually i spinous and 5 soft rays; branchio- 

 stegal rays 6 or 7; air bladder without duct; pyloric appendages present: 

 about 15 famihes, in all seas except the Arctic and in fresh waters. 



Key to the Families of Percoidei occurring in Fresh Water 



ai Ventral fins with rays I, 7; i dorsal fin i. AphredoderidcB. 



2ii Ventral fins with rays I, 3 or 5, typically 5. 



bi Lateral line wanting; i dorsal fin; hinder margin of tail 



rounded 2. ElassomidcB. 



hz Lateral line present (except in Microperca), more or less 

 complete. 

 Ci Lateral line not extending on to the tail. 



di But I dorsal fin, in Micropterus with a deep notch 



between the spinous and soft-rayed portions. . .3. Centrarchidce. 

 d2. Two dorsal fins present. 



Ci Anal spines i or 2 4. PercidcB. 



62 Anal spines 3 5. Serranidcc. 



C2 Lateral line extending on to the tail 6. Scia;nid(B. 



Family i. Aphredoderidae. — Body eUiptical; caudal peduncle thick; 

 scales ctenoid; sides of head scaly; lateral line imperfect or wanting; 

 pyloric caeca about 12; anus below the preopercle in the adult but 

 behind the ventral fins in the young; tail fin rounded: i genus. 



Aphredoderus LeSueur. With the characters of the family: 

 species. 



A. sayanus (Gilliams). Pirate perch (Fig. 50). Length 190 mm.; 

 head 3; depth ^.t,; color dark olive, speckled with dark dots; 2 dark 

 bars at the base of the tail fin; rays of dorsal fin III to IV, 10 to 11; 

 anal II, 6; scales 9 to 13-45 to 60-12 to 14: Long Island to Texas; up 

 the Mississippi Valley to Minnesota and eastward to Lake Erie. 



