112 VERTEBRATE ANIMALS OF THE UNITED STATES 



upper half of body with dark round spots; rays of dorsal fin II, 9; anal 

 I, 7; scales 6-50-7: Delaware and Potomac Rivers to Kansas, and north- 

 ward to Hudson Bay; common in the Great Lakes. 



2. Columbia Eigenmann. Body rather robust; dorsal and anal fins 

 with 2 strong spines each; posterior margin of preopercle with a few 

 short spines; lateral line imperfect: i species. 



C. transmontana Eig. Length 100 mm.; head 3; depth 3.5; color 

 greenish, upper half of body with large dark spots; rays of dorsal fin II, 

 9; anal II, 6; scales 7 to 9-44 to 46-7 : lagoons along the Columbia River; 

 locally common. 



Suborder 3. Percesoces.^ — Ventral fins abdominal, with rays I, 5; 

 dorsal spines few, usually forming a separate fin; scales usually cycloid; 



^Mfif^^^^^m^'" 



Fig. 49. — Labidesthes sicculus {from Fishes of Illinois). 



pectoral fins elevated and on a level with the posterior angle of the 

 opercle: 3 families, mostly marine. 



Family Atherinidae. — Silversides. Body elongate, somewhat com- 

 pressed; pseudobranchiae present; 2 dorsal fins, the anterior with spin- 

 ous rays; anal fin long; no lateral fine; no pyloric cseca; branchiostegals 

 5 or 6: 15 genera and about 60 species, which Hve along the sea coasts of 

 the warmer continents; a few species are found in rivers. 



I . 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. audens Hay. Length 75 mm.; head 4.5; depth 6; color trans- 

 parent green, with a lateral silvery band; rays of dorsal fins IV or V-I, 

 8 or 9; anal I, 17 or 18; scales 45-10: Mississippi River between Vicks- 

 burg and Memphis. 



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 11; anal I, 15 to 18; scales 38 to 40-8; eyes very large: Long 

 Island to the Potomac River, in fresh and brackish water; common 

 locally. 



