PISCES, TRUE FISH 451 



dorsal fin far to the posterior, near the base of the forked tail. Esox 

 lucius, the common pike, and Esox masquinongy, the muskellunge, 

 are familiar northern forms. Esox vermiculatus, the mud or grass 

 pickerel, and Esox niger penetrate the Southwest. 



Suborder Cyprinodontes. — Killifishes, Mosquito Fish, and Cave 

 Fish. 



Family Cyprinodontidae. — Killifishes. This group of minnows, 

 well represented by Funduhts heteroclitus, the common killifish, or 

 Zygonectes notatus, top minnow, are found commonly in shallow 

 estuaries or fresh-water streams. F. heteroclitus is a much used labo- 

 ratory animal along the Atlantic coast. 



Family Poeciliidae. — Mosquito Fishes. This is a very common 

 mosquito-eating fish of the South. Ganibusia is a widely distributed 

 genus. 



Family Amblyopsidae. — Cave Fishes. There are a few species of 

 these small fish living in subterranean streams of the central and 

 southern United States. 



Suborder Synentognathi. — Garfishes and Flying Fishes. 



Family Belonidae. — Sea Garfishes. These are long-bodied, vora- 

 cious fish of the warm seas. They range from Maine to the Texas 

 Coast of the Gulf of Mexico. 



Family Exocoetidae. — Flying Fishes. Some of these peculiar fishes 

 are able to leave the water and glide through the air for several 

 yards. The pectoral fins are greatly developed and serve as planing 

 surfaces. There are about sixty different species inhabiting the 

 tropical seas. 



Suborder Thoracostei.- — Pipefish, Sea Horses, and Sticklebacks. 



Family Syngnathidae. — Pipefishes and Sea Horses. A group of 

 very peculiarly-shaped fishes whose bodies are quite long and slender. 



Family Gasterosteidae. — Sticklebacks. Most representatives of 

 this family have prominent spines just anterior to the dorsal fin. 

 They are principally northern in distribution. 



Suborder Anaca7ithini. — Codfishes. 



Family Gadidae. — Codfishes. These are large-mouthed fish with nu- 

 merous teeth and pyloric caeca. They are food fish of northern seas. 



Suborder Heterosomata. — Halibut Flounders, Soles, and Tongue 

 Fish. (Flat-fishes.) 



