1889 .] 
349 
[Foerste. 
Calymene rostrata is found in the Clinton of New York and 
Georgia ; it is not found in the Clinton of the anticlinal, but is rep- 
resented in the Niagara of Indiana by C. riasuta. 
What adds to the interest of these occurrences is the fact that at 
the present moment the fossils of the Clinton of Ohio at least are 
as well known as, if not better known than those of any of the 
eastern localities. 
It will also be noticed that the forms in question are the more 
common species, having in some cases a wide geographical range, 
a number of them being transatlantic. They also have often a 
fair vertical range, so that forms occurring in the Clinton of the 
east, but only in the Niagara of the west, are also usually found in 
the Niagara in the east. 
At first thought the explanation might seem simple : the Clinton 
of Ohio represents the earlier sedimentary deposits of the Clin- 
ton and hence does not present many fossils found in the later de- 
posits of the east. But continued study does not bear out such an 
assertion. The Clinton forms of Ohio and Indiana show a more 
advanced stage of development than do the Clinton forms of New 
York ; the types are decidedly Niagara and in larger percentage 
than in the Clinton of New York, but certain species are wanting 
in Ohio and Indiana Clinton which occur in the Clinton of New 
York, and which are there associated with forms belonging to as 
early a period in the history of the Clinton as the Clinton of the 
anticlinal, if not earlier. But in anticlinal regions these forms do 
not occur until at a later date, namely, the Niagara. 
The Clinton as represented in Anticosti is closely linked with 
the Lower Silurian and the Niagara. The Clinton of Pennsylva- 
nia shows but slight advance over the Clinton of New York. The 
Clinton of Tennessee is about on the same level with that of Penn- 
sylvania. The Clinton of Alabama as here described shows more 
marked affinities towards the Niagara than do the corresponding 
formations in Tennessee and Pennsylvania. And yet the solution 
of the problem, why certain forms are not represented in the Clin- 
ton of the anticlinal, does not seem to depend upon facts relating 
to the greater affinity of some of the eastern Clinton formations 
with the Niagara, since most of the forms in question appear in 
the Clinton of New York, believed to be of earlier age than the 
Clinton of the anticlinal, and also in Pennsylvania, where the Clin- 
ton does not differ substantially in age from that of New York. 
Two suggestions may be offered as to the peculiar distribution 
