In the classification presented here, the Semionotiformes include the living gars as well as certain fossil fishes known as semionotids. The modern bowfin (Amia calva) is the lone survivor of a second main group of neopterygians, the Halecomorpha, which was once more diverse and abundant. Finally, the Teleostei include most living ray-finned fish, in addition to some fossil groups that are most closely related to them.
At the base of the neopterygian tree are several groups of early neopterygians, including the oldest known neopterygians of the Mississippian. For the moment, we have grouped these under their traditional name of "paleoniscoids," but remember that this is a paraphyletic grouping.
For more detailed information on bony fish classification, try the Actinopterygii pages from the Tree of Life at the University of Arizona.
This seven-language fish dictionary is available from the Marine Research Institute of Iceland.