Devonian Plants from Ohio. 49 



gives in his illustrations of the vegetation of the different ages, one 

 picture of the Devonian flora. This represents dry land bearing 

 large trees of Lepidodendron and marshes filled with the imaginary 

 Stigmaria, now demonstrated to be nothing else than stumps and 

 roots of Sigiliaria and Lepidodendron ; the trunks and branches 

 having decayed and disappeared, the roots and rootlets being pre- 

 served in clay or carbonaceous marsh mud. 



Later Sir William Dawson added greatly to our knowledge of 

 the Devonian flora by the study of the large collection of fossil 

 plants made near St. John's, New Brunswick, and at Gaspe, Can- 

 ada. The plant bearing beds of these localities belong mostly to 

 the upper part of the Devonian system, but are clearly older than 

 the Lower Carboniferous rocks with which they are associated. Sir 

 William Dawson has now described nearly two hundred species of 

 Devonian plants, and has shown that the botanical character of the 

 Devonian flora is essentially the same as that of the Carboniferous 

 system, as it includes Lepidodendron, Sigiliaria ^ Cordaites, Sphe- 

 nophyllum, Calamites and many ferns, mostly of Carboniferous 

 genera. 



The fossil plants from New York, described by Sir William 

 Dawson, Hail and Vanuxem, are from the Chemung or Catskill 

 rocks, which have been heretofore considered as the uppermost 

 portion of the Devonian system, but in my judgment should rather 

 be regarded as the basal members of the Carboniferous. The same 

 is true of the fossil plants from Perry, Maine, first brought to the 

 notice of geologists by Prof. William B. Rogers, at the Newport 

 meeting of the American Association in i860, and afterward 

 described by Sir William Dawson (Journal Geological Society of 

 London* 1863, page 450). 



The plants now described from the Corniferous limestone of 

 Ohio, are from about the middle of the Devonian system, having 

 the Oriskany below and the Hamilton above. They are all from 

 the Delaware limestone, the upper division of the Corniferous. It 

 has been thought by some that this should be regarded as Hamil- 

 ton rather than Corniferous, but as I have shown in my discussion 

 of this subject, in the Geological Report of Ohio, Vol. III., p. n, 

 the testimony of the fossils contained in it is opposed to this con- 

 clusion; nearly all being found in the white or Sandusky limestone 

 below. The Delaware limestone is much darker and more earthy 

 than the lower division of the Corniferous, and it is evident that it 



