CORRELATION, OF THE, DEVONIAN FAUNAS IN 
SOUTHERN ILLINOIS. 
INTRODUCTION. 
Tue Devonian faunas of the interior of America are of two 
distinct types, and occur in two more or less distinct geological 
provinces. The eastern interior province is typically represented 
in New York; it extends westward into Canada and southwest- 
ward into the Ohio valley. The western interior province is 
typically represented in Iowa; it extends to the northwest into 
British America and is connected with the European region. 
The southern Illinois Devonian is of much interest because of its 
geographic position between the New York and the Iowan areas, 
but in all the study which has hitherto been devoted to the 
region, it has never been definitely shown with which one of 
these provinces it is connected. Recent investigation shows the 
Devonian faunas in southern Illinois to be intimately related to 
the New York faunas, and that the strata containing them are 
but a western extension of the formations of the eastern province. 
The ‘“ Devil’s Back Bone” and the ‘“ Devil’s Bake Oven,” near 
Grand Tower, in Jackson county, Illinois, have long been recog- 
nized as localities rich in Devonian fossils. In 1855 Norwood 
and Pratten’ described as new several species of Chonetes from 
this locality. In 1867 Hall made frequent mention, in Vol. IV of 
the Paleontology of New York, of the occurrence of species of 
brachiopods at the ‘‘ Bake Oven,” Jackson county, IIlinois, anda 
few were described from this locality exclusively. In 1868 the 
geology of Jackson county was published in Vol. HI of the 
Geological Survey of Illinois, several sketches of the ‘Bake 
Oven” and the ‘‘Back Bone” being reproduced and mention 
being made of the fossils collected. In the same volume are 
tJour. Acad. Nat. Sci., Phil., ser. 2, Vol. III, pp. 23-32. 
625 
