In Carboniferous and Permian Epochs 159 



a thick bed of cubical coal, of which the place is near 

 the top of the Lower Coal Measures. This is a bed of 

 coal which extends over some thousands of square miles, 

 and it is usually a soft coking coal, not unlike that of the 

 Pittsburg seam, which lies about 500 feet higher. At 

 Linton, however, we have evidence that the great marsh 

 in which the peat accumulated that formed Coal No. 6 

 was for a time a lake or lagoon, inhabited by the fishes or 

 amphibians to which I have referred. While this remained 

 an open body of water carbonaceous mud accumulated at 

 its bottom, cierived from the drainage of the neighboring 

 marsh, which carried with it fine particles of completely 

 macerated vegetable tissue. In this carbonaceous mud that 

 is now cannel coal, were buried the scales, bones, spines, 

 and often entire individuals of the inhabitants of the waters 

 above. Sometimes nearly the whole mass is made up of 

 animal debris. Many of the fishes and amphibians were 

 highly carnivorous and powerful, as we learn from their 

 teeth and coprolites." 



Chamberlin describes life in the North American coal 

 areas (5:11:6x3) as follows: "Aside from the develop- 

 ments of the freshwater fish and of the amphibians, which 

 have already been sufficiently emphasized, perhaps the most 

 suggestive feature was the association of the arthropods 

 with other forms of life. Eurypterids were still in exist- 

 ence, and their relics are so intimately associated with 

 beautifully preserved ferns, calamites, insects, spiders and 

 scorpions, as to leave no reasonable doubt that they were 

 freshwater forms. In the more notable localities, as at 

 Mazon Creek, Illinois, and Cannelton, Pennsylvania, the 

 fern fronds were preserved with almost perfect fidelity and 

 without the coiling, crumpling and shredding that would 

 have inevitably attended transportation for any notable 

 distance. At the famous locality on Mazon Creek, un- 

 crumpled fronds form the centers of thousands of con- 

 cretions, and insects, spiders, scorpions and eurpyterids 

 form the centers of others associated with them. All must 

 have been fossilized with a minimum of transportation, 

 and under the most quiet conditions. Almost equally in- 



