OF DENISON UNIVERSITY. 
9 
Clinton fauna of Ohio, however, is not at all like that of the Guelph 
in character, hut it possesses some feautures in common with that of 
the Waldron beds, and a small number of identical species. This 
would indicate a lower horizon for the Waldron beds than for the 
Guelph beds, and a still lower one for the Clinton beds of Ohio. The 
fact that the Clinton Group of Ohio contains a number of fossils sig- 
nifying a low horizon, such as Rhmopora verrucosa, Phylloporina angu- 
lata, Leptoena prolorgata, Strophoineiia patenta, Merstella umhonata, 
Bellerophon fiscello-striatus, and Disco soriis conoideiis, and the fact 
that the Waldron beds have no such types, is additional evidence in fa- 
vor of the lower horizon of the Clinton Group of Ohio. I'hat the 
Clinton Group of Ohio should begin to assume the Gcies of the Wal- 
dron beds of Indiana, and the Waldron beds of Indiana, that of the 
Guelph series above, are facts which the paleontologist will recognize 
as being of frequent occurrence, and indicating consecutive develop- 
ment of life. Moreover, it is not necessary to imagine that the vari- 
ous strata mentioned must either be exact equivalents or entirely dis- 
tinct from one another. While life ceased at one locality it was still 
continuous for sorr.-e time at another, more or less removed, and new 
types gradually introduced in those localities where life has been con- 
secutive, seem to have been introduced suddenly into the locality 
where life for a while had ceased, whereas it is only a case of the re- 
introduction of a faunna in one place after life had ceased for some 
time, from some other locality where life had been continuous, and 
where the change of the fauna had been gradual. ' Geological divis- 
ions are after all only convenient methods of reference, and divisions 
are regulated largely according to the number of breaks in the faunal 
development of any region. Every experienced paleontologist, how- 
ever, knows that what are breaks in the development of life at one 
place are gradually bridged over at some other locality, d his feature 
is in small part shown by the Clinton and Waldron beds of the West. 
Indeed, the Clinton of Ohio is itself a connecting bridge between the 
Clinton and Niagara, as shown in New York, and Dr. E. N. S. Ringue- 
berg has found another connecting bridge at Lockport, N. Y., be- 
tween the divisions themselves. Again, the Anticosti Group of Cana- 
dian geologists is a connecting bridge between the Upper and Lower 
Silurian series of rocks. This illustrates the fact, well known among 
students of ancient life, that geological divisions are not universally 
