THE SEPTARIA. 121 



hammer of the inquisitive geologist, for fre- 

 quently in the center of these globe-like con- 

 cretions fossil specimens have been discovered. 



It was in one of these that the Hertzeri Di- 

 nichthys was found by Eev. Henry Hertzer, 

 then of Delaware, Ohio. 



This gorge is known locally as Fern Canyon. 

 The Branch, after passing through this inter- 

 esting channel, whose outlet of boulders is much 

 like the terminus of a glacier on a small scale, 

 runs sluggishly for a short distance through 

 a strip of alluvial lowland and joins its waters 

 to those of the Olentangy. 



Upon first sight, these mysterious looking 

 spheroids strike the mind of the novice with 

 wonder, and never cease to be full of interest. 

 In the Geological Survey of Ohio, Dr. Orton 

 makes frequent reference to them, as in the 

 following : 



"One of the most conspicuous features of the 

 Huron shale is found in the concretions, great and 

 small, which it contains in great numbers. They be- 

 gin with the formation, and in the lowermost forty 

 feet all the varieties of their structure can be seen. 

 The shape which the larger and more symmetrical 

 take is that of flattened spheroids. Not infrequently 

 two are joined together by a ligament uniting their 

 centers. They are sometimes, but more rarely, disc- 

 like, and many of them lack regularity of outline. 



