r.ff-quereiix.] 40- fj;in.5, 



the scars of very dilVerent size. Some correc ions liave to be made, as said 

 al)ovc', but certainly not more than would be demanded for a work of this 

 kind, pursued under the most unfavorable circumstances, twenty years after 

 its piihliration. 



Alter the close of the survej' or of the exploration under the direction of 

 Prof H. D. Rogers, I had continued, on my own account and at my own 

 expense, the explorations for the s:udy of the coal plants of the antliracite 

 fields of Pennsylvania. In the fall of 1857, while stopping at Pottsvillc for 

 the examination and determination of a large lot of specimens of fossil 

 plants in the cabinet of the Pottsville Scientific Association, I was requested 

 by some members of the society to prepare a catalogue of all the species 

 which had come under my examination in Pennsylvania and other States, 

 including the species which I had then recognized in the Pottsville cabi- 

 net. This catalogue, delivered February 1858, was immediately pub- 

 lished. It comprises the names of 286 species, including those copied from 

 a list of the species of coal plants from Ohio by Dr. Newberry. Most of 

 the species described in my report to Prof Rogers are named, and form the 

 largest part of it ; some however being left out as uncertain, others added 

 and described and figured as new. No reference is made in this catalogue 

 to the Pennsylvania Geological Report for the good reason that I did not 

 know if this report should ever appear in print. But as the new species 

 described in it had been already published, and their names were thus 

 public property, and as the others were those of species described by 

 European authors, I was then and am now still unable to see how the 

 publication of this catalogue could be considered as a breach of litx-rary 

 obligation, according to the expressions of the Pennsylvania report, p. 878. 

 It is certainly needless to say any more on the subject. 



I had at that time become acquainted with the fossil flora of the Penn- 

 s^-lvania coal measures quite as sufficiently as I thought needful for 

 my purpose, and I was anxious to pursue the exploration in other coal 

 fields in order to be able to study the characters of the vegetation of the 

 coal at distant localities, for the elucidation of more important questions, 

 those especially referable to the geographical and stratigraphical dis- 

 tribution of the species at the carboniferous period. For it would not do to 

 attempt to expose a history of the American coal flora merely from data 

 obtained in Pennsylvania. With this idea I began a new series of field explo- 

 rations, and the examination of all the collections of fossil plants to which 

 I could gain access ; and this work has been pursued nearly uninterruptedly 

 until now. First I went, twice, along the Ohio river from Pomeroy down to 

 Gallipolis, and up the Kenawha river to the salines of Charlestown, Vir- 

 ginia. I liad then the opportunity to see the cabinet of Dr. Ilildreth at Ma- 

 rietta, and to begin with this justly venerated geologist a series of relations 

 and mutual communications coniinucd to his de.ith. At Charles'own I had 

 access to a fine cabinet of specimens of the Hev. Mr. Brown, who had a num 

 ber of in'eresting and new species. I collected mj-.self good material for study 

 in the mines worked thm above that place. I visited the more interesting 



