Io6 VERTEBRATE ANIMALS OF THE UNITED STATES 



bo Lateral line present (except in Microperca), more or 

 less complete. 

 Ci Lateral line not extending on to the tail fin. 

 di But one dorsal fiji present (the spinous and 

 soft-rayed portions being joined); sunfish 



and black bass 3. CentrarchidcB. 



d2 Two dorsal fins present (the spinous and soft- 

 rayed portions not being joined), 

 d Anal spines i or 2. 



fi Pseudobranchiae well developed; pre- 

 opercle serrate; branchiostegals 7; 



perch and pike 4. Percidce. 



f2 Pseudobranchiae imperfect or wanting; 

 preopercle not serrate; branchio- 

 stegals 6; darters 5. EtheostomidcB. 



62 Anal spines 3 6. MoronidcB 



C2 Lateral line extending on to the tail fin 7. Scicenidce. 



Family i. Atherinidae. — Silversides. Body elongate, somewhat 

 compressed; pseudobranchiae present; 2 dorsal fins, the anterior with 

 spinous rays; anal fin long; ventral fins abdominal, with rays I, 5; no 

 lateral line; no pyloric caeca; branchiostegals 5 or 6: 15 genera and 

 about 60 species, which live along the sea coasts of the warmer con- 

 tinents; a few species are found in rivers. 



Fig. 50. — Labideslhes sicculiis {from Fishes of Illinois). 



1. Menidia Bonaparte. Body elongate; mouth small, very 

 oblique ; premaxillaries protractile; teeth in bands, none on the palatines 

 or vomer; a silvery band along the sides; tail fin deeply forked: 10 

 species, all American, mostly marine, some entering rivers. 



M. beryllina (Cope). Length 65; head 4.3; depth 5 to 5.5; color 

 pale olive with a well defined lateral silvery band; rays of dorsal fins 

 V-I, 9 to II ; anal I, 15 to 18; scales 38 to 40-8; eyes very large : Massa- 

 chusetts to Florida; lower Mississippi; Tennessee, in fresh and brackish 

 water; common locally. 



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

 duced to form a short beak: i species. 



