Report of the Sub-Committee on Upper 
Paleozoic (Carbonic).* 
J. J. STEVENSON, 
KEPOETER. 
A SUBSTANTIAL agreement as to a general grouping of the Car- 
bonic appears in the communications received, but there is clearly 
no small difficulty in making subordinate divisions. The enor- 
mous area of our country, the distances separating the several 
regions of Carbonic, and the striking differences in geological 
conditions, even within the same areas, make the problem as 
perplexing as that of preparing a general scheme for the Car- 
bonic of all Europe. 
The succession of beds is separable into 
Upper Carbouic,t 
Lower Carbonic, 
which in by far the greater part of the country are well defined 
both physically and paleontologically. The Upper Carbonic is 
recognized readily in all of the regions, but the Lower Carbonic, 
* Letters of inquiry were sent to those geologists who have spent much time 
in the study of the Carbonic. Keplies have been received from Profs. Cope, 
J. W. Dawson, Lesley, Newberry, Safford, Smith, Walcott, C. A. White, I. C. 
White, A. Winchell and Worthen. 
t The use of the terms " Upper " and " Lower " has been objected to by 
many, and rightly enough ; but where variations are so great as in the Car- 
bonic, there seems to be no possibility of employing any geographical terms, 
and the only way out of the difficulty would be the invention of some mean- 
ingless names. But the terms " Upper " and " Lower " have been a part of 
the literature so long that to change them now, without absolute necessity, 
would not meet with the approval of any. 
