area east of the Rockies except extreme northern U. S. 



Luxilus cornutus chrysocephalns (Raf.) Central Common 



Shiner 

 7\[otropis cornutus chrysocephalus (Raf.) 



272. With two to eleven free spines before the dorsal fin; Family Gasteros' 



teidae Sticklebacks 273. 



With spines contained in the anterior part of the dorsal fin or in a finlet 



preceding it 276. 



273. With seven to eleven free spines before the dorsal fin; north Atlantic 



coast and Great Lakes region 



Pungxtius pungitius (Linn.) Nine-spined Stickleback 

 With two to six free spines before the dorsal fin 274 



274. With small bony plates on the sides; ascending streams from the Atlantic 



and Pacific 



Gasterosteus aculeatus Linn. Common Stickleback 

 (Includes Gladiunculus hispinosus (Walbaum) ) 

 No such plates 275. 



275. With three free dorsal spines; north Atlantic coast 



Apeltes quadracus (Mitchill) Four-spined Stickleback 

 With four to six free dorsal spines; N. Y. to Kansas, in fresh water 

 Eucalia inconstans (Kirtland) Brook Stickleback 



276. With one or two spines in the anterior end of the dorsal fin 277. 

 Dorsal fin with an anterior spinous portion containing four or more 



(rarely three) spines 284. 



277. Outline of tail convex; Florida (a killifish, Family Cyprinodontidae) 



Jordanella floridae G. & B. Florida Killifish 

 Tail fin forked 278. 



278. With one dorsal spine, which is strongly serrate behind; this spine may 



or may not be preceded by a smooth spine; adult fishes eight inches 

 or more long; introduced species which have become established in 

 ponds and streams; Family Cyprinidae (part) 279. 



Dorsal spine double, the posterior one fitting into a groove in the an- 

 terior one; very small fishes; mostly confined to the southwest (Colora- 

 do, Nevada and Ari2,ona) ; Family Medidae 28 L 



279. With two barbels' on each side of the upper jaw; an introduced Asiatic 



species, which has become well established 

 Cyprinus carpio Linn. Carp 

 No barbels; an introduced genus common in pet shops and frequently 

 becoming large and established from escapes; adults gold or remaining 

 greenish throughout life 280. 



280. Scale count twenty-seven or less; with seven or eight rays in the anal fin 



Carassius auratus (Linn.) Japanese Goldfish 

 Scale count twentyeight or more; with five or six soft rays in the anal 

 fin 



Carassius carassius (Linn.) European Goldfish 



28 L Body with scales 282. 



Body scaleless 283. 



290 



