PAPERS OX GEOGRAPHY AND GEOLOGY 335 



FISHING WITH A HAMMER 



Fred R. Jelliff, President of Knox County Academy 

 of Science, Galesburg 



I presume that you all enjoy fishing with hook and 

 line, but there is pleasure also in angling with a hammer. 

 For a number of years I have found recreation in the 

 examination of a layer of slate over a seam of coal five 

 miles east of Galesburg due to the fish remains that it 

 contains, and not merely fish but reptilian, crustacean, 

 amphibian and molluscan. In a way it can be said to 

 illustrate all the great kingdoms of animal life. This 

 coal vein is probably what is known as No. 3 of the Illi- 

 nois series, and it dips to the southeast at about the same 

 angle as Court creek, so that when one reaches Spoon 

 river he finds in places this slate and coal in its bed. 



But the scene of our investigation is east of the city 

 and is in and just above Court creek channel. On the 

 south side of this is a high and steep bluff exposing the 

 friable and bluish, and the ironstone layers and a heav- 

 ier fossiliferous limestone and clay shale that lie above 

 the slate. It is in this slate that one finds the remains of 

 ancient fishes, for which but few counterparts are now 

 known to exist. 



We have compressed here in a very few feet a remark- 

 ably intermingled community of life forms. The slate 

 varies much, some of it splitting into thin leaves, the 

 surface of which may appear smooth save for an occas- 

 ional fish spine or tubercle, and others being filled with 

 nodules or elongated concretions that cannot be readily 

 split. The probability is that the slate was deposited 

 far enough from the shore to permit the accumulation of 

 the finer vegetable sediment, for the slate is fine grained 

 and consists of very thoroughly ground up vegetable 

 material. In the nodules one often finds interesting speci- 

 mens of the life of that ancient sea. These are composed 

 of a much harder material than the slate, and constitute 

 caskets around the remains of what were once organic 

 beings. Usually by a careful application of the hammer 

 on one end, the nodule will split open and disclose the 

 specimen. 



