12 
BULLETIN OF THE LABORATORIES 
als, although present to a moderate degree, do not form a marked fea- 
ture of the enclosed fauna. However, this is the line in which there 
is a considerable variety in the number of trilobites, brachiopods, and 
bryozoa. It is especially of value, however, as containing the best 
general collection of the fossils peculiar to the group in the best con- 
dition for the collector’s purposes. The localities in line with Reed’s 
Hill, Camp Corwin and the Huffman quarries are the worst localities 
for collectors of specimens. However, beginning at Huffman’s quarry 
there are a few fossils at the very top of the Clinton proper, and the 
fauna of the Beavertown marl is also shown. At Centreville the top 
of the Clinton proper reaches a greater variety in the fauna, and at 
Todd’s Fork, where there is a commingling of the two, the top strata 
are quite richly fossiliferous again. The question presents itself 
whether this distribution of the fauna can have any relation to the ele- 
vation of the Cincinnati Arch. If so, it would be a most indubitable 
evidence of the elevation of that arch before the beginning of the 
Clinton Group. 
If there is so much variation in the fauna of even a quite limited 
district it will be well to note what forms have been found most relia- 
ble in the identification of this group, forms therefore which are char- 
acteristic and have the widest geographical range. These are: IllcR- 
niis Daytonensis, Illozniis ambiguits, Dalmaniies 'Wertherni, Platyostomus 
Ntagarense (a small and constant form) Orthis flahella^ Strophomena pa- 
tenta^ Phylloporina angulata, Clatliropora frondosa, Ptilodictya expansa^ 
the various species of PhcEnopom and Rhinopora verrucosa. Any local- 
ity in this state or in Indiana, containing five of these species, could 
safely be referred to the Clinton Group as represented in Ohio. 
