E. Orton — Bituminous matter in Ohio Black Shah s. 1 7:; 



some pieces acquire a rusty or yellowish color, even to the 

 naked eye, from their aggregation. 



At a later date I found the upper member of the great black 

 shale in the vicinity of Columbus (the Cleveland shale), 

 charged with identical forms. In addition to the discs already 

 described there are occasionally found in this stratum flattened 

 spheroids, considerably larger in size and somewhat darker in 

 color, but obviously referable to the same group of forms. 

 These larger bodies range from one fifty-fourth to one sixty- 

 fourth of an inch in their long diameters, and consequently are 

 discernible by the naked eye when thev are well located. 

 They burn with a flame and leave no residue. 



I have lately examined specimens of the black slates of the 

 three horizons named, viz : the Huron, the Cleveland and the 

 Berea shale, from every part of the State in which they occur, 

 and I find forms agreeing in general characters with those first 

 described, everywhere present and often in great numbers. I 

 am not now prepared to make computations of the number 

 present in any measured volume of the shale, but the pro- 

 portion is a notable one in many instances. 



As to the nature of these bodies there seems no reasonable 

 room for doubt. They agree in general characters with the 

 spore-cases of several of the lower orders of plants. The 

 -on of the lycopodiaceous spores 

 in English coals will apply without change to the general 

 appearance of these forms, in sections parallel and trans- 

 verse to the bedding, but they lack the peculiar markings and 

 shapes that characterize lycopod spores in particular, and will 

 probably find their place in some lower group. 



Different sizes have been recorded for these forms, but there 

 is no doubt that all of them are macrospores. The finely- 

 divided carbonaceous matter that is associated with them in 

 the shale may represent the microspores. 



There is nothing new in the detection of spores in forma- 

 tions that agree in general character with these black shales. 

 Williamson records the presence of lycopod spores in great 

 numbers in British fire-clays and iron ores. Binney has urged 

 the view that the Boghead Cannel and other similar deposits 

 must be referred to microspores for their origin. 



The two inflammable Australian minerals, white coal and 

 tasmanite, have been shown by microscopic sections to owe 

 their inflammability to the resinous spores of lycopodiaceous 

 plants. These minerals belong to a much later geological 

 period than the Carboniferous. The tasmanite above referred 

 to is a shale containing 26 to 30 per cent of combustible mat- 

 ter. It is then 1. re i it itt e richer than the best portions of 

 our Berea shale, which contain 21/4 per cent of bituminous 



