20 J. W. Dawson on Paleozoic Bhizocarpa. 



They occur in a brown bituminous shale, which burns with much 

 flame. This bed is stated in the report of the Geological 

 Survey of Canada to be twelve to fourteen feet in thickness, 

 but whether the fossils are equally abundant throughout its 

 thickness is uncertain. The shale also contains vast numbers of 

 rounded transparent granules, which may be escaped spores or 

 microspores. 



The only other fossils found in this bed are stems of a species 

 of Calamities (C. .inornatus) , and a Lepidodendron obscurely pre- 

 served, but not improbably the S. primaevum of Rogers. My 

 impression at the time when these spore-cases were first examined 

 was that they might have been produced by a Lepidodendron or 

 other lycopodiaceous plant. 



In July, 1882, my attention was again directed to the subject 

 by Prof. Orton, of Columbus, Ohio, who mentioned to me the 

 occurrence of similar bodies in vast numbers in the Erian and 

 Lower Carboniferous shale of Ohio, known as the Huron, 

 Cleveland and Berea shales. Prof. Orton regarded these bodies 

 as spore-cases, and was disposed to consider them as a main 

 source of the bituminous matter so abundant in these formations 

 in Ohio. He subsequently detailed his observations at the meet- 

 ing of the American Association at Montreal, and referred to 

 certain thread-like branching stems found with these bodies as 

 possibly connected with them. Though this observation did not 

 seem to be absolutely certain, yet in connection with the very 

 wide distribution of the organisms in marine beds it served to 

 shake the belief which I had formerly entertained as to the 

 lycopodiaceous affinities of the Sporangites Muronensis, which on 

 comparison I found some of Prof. Orton's specimens precisely 

 resembled 



For the geological facts relating to the mode of occurrence of 

 the Ohio specimens, I may refer to Prof. Orton's paper, which 

 appears in the proceedings of the American Association ; merely 

 stating that he describes the Sporangites as occurring through- 

 out the thickness of the Ohio black shale, amounting to 250 to 

 300 feet, and which extends over a very wide area in Ohio and 

 the neighbouring states. 



At the meeting of the American Association, in the discussion 

 of Prof. Orton's paper, Prof. Williams, of Cornell University, 



