PISCES, TRUE FISH 455 



Suborder Jugulares. — 



Family Batrachoididae.— Toadfishes. This group includes a num- 

 ber of species which have large mouths and somewhat the appearance 

 of toads. 



Suborder Pledog^iathL—Trigger^hes, Filefishes, and Porcupine 

 Fishes. 



Family Balistidae. — Triggerfishes. The spines of the dorsal fins of 

 these fish are long and saw-toothed. 



Family Monacanthidae.— Filefishes. The body of this type of fish 

 is much compressed and covered with rough, velvety skin. The fins 

 are poorly developed. 



Family Diodontidae.— Porcupine Fishes. The fixed spines on the 

 bony plates in the skin are characteristic of the group. 



Suborder Pediculati. — 



Family Lophiidae. — Anglers. A heavy appearing, broad-bodied 

 fish. The first spine of the dorsal fin is extended and enlarged at the 

 tip to hang over the mouth as a bait for other fish. 



Subclass Dipnoi.— Lungfishes. These fish have long, slender, paired 

 fins and a well-developed median fin. The air bladder is connected 

 with the pharynx and is modified to serve as a lung. They possess 

 characteristics which apparently place them intermediately be- 

 tween fishes and Amphibia. There are only three living genera. 



Family Ceratodontidae.— Australian Lungfish. There is only one 

 species in this family and it is Neoceratodus fosteri, found in stag- 

 nant waters of Australia. This species is able to breathe air. 



Family Lepidosirenidae. — Lungfishes of South America and Africa. 

 Proiopterus is the genus found in the marshes of Africa. They feed 

 on insects, worms, crustaceans, and smaller vertebrates. They go 

 into aestivation by burrowing into the mud of the marshes during the 

 dry summer season. Here they secrete a cocoon of slime for protec- 

 tion. Respiration is carried on by two lungs formed from a modified 

 air bladder. Lepidosiren paradoxa is the single form found in South 

 America. 



Economic Relations of the Class 



Fish have been one of the stable sources of food for man all 

 through history, and it is in this respect that they are most impor- 

 tant to man in present times. H^idreds of millions of dollars 



