FISHES 93 



E. niger LeSueur. Common pickerel; chain pickerel. Length 

 600 mm.; head 3.5; depth 6; color green; sides marked with numerous 

 irregular dark lines forming a network; a dark band below the eye; 

 fins plain; rays of dorsal fin 14; anal 13; scales 125; branchiostegals 14 

 to 16: Atlantic and Gulf slope, Maine to Florida and Louisiana; very 

 numerous in the New York lakes and east and south of the Alleghenies. 



E. vermiculatus LeSueur. Grass pike; little pickerel. Length 

 300 mm.; head 3.25; depth 5 to 6; color green or grayish, sometimes 

 plain but usually with an irregular network of dark streaks on the sides; 

 a dark bar downward from the eye; rays of dorsal and anal fins 1 1 or 12; 

 body rather stout; scales 105; branchiostegals 11 to 13: Mississippi 

 Valley and the southern tributaries of Lakes Michigan, Erie and 

 Ontario; common. 



E. americanus Gmelin. Banded pickerel. Length 300 mm.; head 

 3.6; depth 5.5; color dark green; sides with about 20 blackish curved 

 bars; rays of dorsal and anal fins 11 or 12; scales 105; opercle fully 

 scaled: coastwise streams and ponds from Maine to Florida; common. 



Order 7. Cyprinodontes. — The killifishes. Dorsal fin single, 

 posteriorly inserted; ventrals abdominal, when present; head usually 

 scaled; upper jaw formed by the premaxillaries; size small: 3 families. 



Key to These Families 



El Eyes normal. 



bi Anal fin of male normal i. Cyprinodontidce. 



b2 Anal fin of male very long and inserted forwards 2. PceciliidcE. 



a2 Eyes very small or hidden in the skin 3. Amblyopsidce. 



Family i. Cyprinodontidae. — Killifish. Small fish with moder- 

 ately elongate body, flattened head and rather large cycloid scales; head 

 more or less scaly; mouth small, terminal, with a projecting lower jaw; 

 upper jaw very protractile, its margin formed by the premaxillaries; 

 branchiostegals 4 to 6; tail not forked; no pyloric caeca; no lateral line; 

 many species ovo viviparous: about 30 genera and 180 species, occurring 

 in fresh and brackish water in all the warmer waters of Europe, Asia, 

 Africa and America; about 30 fresh water species in the United States, 

 largely in coastwise inlets and swamps of the southern States. 



Key to the Fresh Water Genera of Cyprinodontidae and Poecillidae in the 



United States 



ai Lower jaw usually projecting beyond the upper; teeth little 

 movable; species mostly carnivorous, 

 bi Anal fin of male of normal shape; species oviparous {Cyprinodontidce). 

 Ci Teeth pointed, and neither bicuspid nor tricuspid. 



