I 



Maryland Geological Survey 109 



Eelations of the Faunas to Sediments ' 



It has been supposed until recently that the Onondaga sediments and 

 fauna were absent from Maiylaud. This view prevailed generally until 

 the writer " found that the Onondaga fauna could be traced southwestward 

 from eastern New York across eastern and central Pennsylvania into 

 Maryland. In passing across the State of Pennsylvania many of the 

 species which characterize tlie Onondaga limestone fauna of New York 

 are found to drop out and to be replaced by others which are unknown 

 in New York. Hence it is not at all surprising that the geologists who 

 have studied the fauna found in the lower part of the Romney of Mary- 

 land, without having an opportunity to compare it with the fauna of the 

 same horizon in Pennsylvania but intermediate in facies between the 

 Onondaga fauna of Marjdand and that of New York, failed to recognize 

 it as the equivalent of the latter fauna. The commonly accepted belief 

 in a high degree of uniformity in the character of the Onondaga and 

 Hamilton faunas throughout the eastern part of America has also mili- 

 tated strongly against the recognition of the basal fauna of the Romney 

 of Maryland as a provincial Onondaga fauna. This preconception has 

 influenced the judgment of stratigraphers and paleontologists alike. The 

 latter have expected formations and the former faunas to show about the 

 same characteristics in the middle Alleghany region which they do in 

 New York. The great provincial differences which the work of several 

 geologists has demonstrated to characterize Upper Devonian faunas which 

 lived in different parts of the same sea have been assumed to be peculiar 

 to the late Devonian and not common to the Middle and Lower Devonian. 

 This generally accepted view has been foi-mulated by one geologist in the 

 following statement: 



" During Upper Devonian time the faunas of the Eastern Continental 

 Province were far more local in their development than they had been at 

 any time during the Middle Devonian. At no time during the jieriod was 

 there so uniform a fauna as either the Onondaga or the Hamilton had been, 

 distributed through the entire province." 



^ Contributed by Edward M. Kindle. 

 ' Bull. U. S. Geol. Survey, No. 508, 1912. 



