560 THE AMERICAN NATURALIST. 
Devonian lung-fishes. By this time the gigantic Chimeeroids 
(Paleomylus, Ptyctodus ferox, Phlyct thus, etc.) had dis- 
appeared; the ubiquitous Ptyctodus calceolus, it is true, persisted 
for a while through sheer force of numbers, but after the State 
Quarry epoch is met with no more. Cladodonts seem to have 
had a continuous existence throughout this period, appearing 
first in the Lower Devonian of Campbellton, New Brunswick 
(Protodus, Doliodus, etc.), but they do not appear to have 
migrated west of Wisconsin until the Carboniferous. They did 
not fairly enjoy their ascendency until after the lung-fishes had 
suffered a decline. 
