FOSSIL PLANTS. 495 



well marked, that their specific value is beyond question. The case is still 

 more evident with Neuropteris verlencefolia, with which we now have a more in- 

 timate acquaintance, from the discovery of a number of specimens, all found 

 at Mazon creek. I mention only these species, not merely as a kind of vindi- 

 cation in favor of our American discoveries, but in order to secure points of 

 comparison in considering the geographical distribution of the plants of the 

 Carboniferous epoch. 



No more evident proof of the truth of what is said above could be afforded, 

 than the discovery in the nodules of Mazon creek of numerous specimens of 

 organs, which have as yet scarcely been found elsewhere. The fructification 

 of ferns and their rhizomas, are of this kind. Besides two of the species de- 

 scribed in the genus Staphylopteris , we have, in nodules from this locality, 

 seven fruiting species of Alethopteris^ six of Pecopteris, with one Asterocarpus , 

 most of which were as before unknown in fructifications. And if the fossil 

 fruit-dots of ferns were not generally obscured, and their form and position in- 

 distinct, discernible only, as they are, through the substance of the leaves, we 

 should have had for description a far larger number of fruiting specimens of 

 ferns. When Prof. Brongniart published his justly celebrated Fossil Flora 

 (1848), only three species of ferns, Pecopteru cyathea, P. hemiteloides and P. Mil- 

 toni, were known and described, with fruiting branches. No fruiting racemes, 

 like those of a Staphylopteris, had then, nor have been found even now, after 

 forty years of further researches in the Coal Measures of Europe. 



Considering this peculiar scarcity of fruiting ferns, Schimper comes to the 

 conclusion that, as arborescent ferns of our time are rarely fertile, the species 

 of this 2;enus, in the Carboniferous epoch, were mostly fern trees. I should 

 be inclined to admit the same conclusion, especially in considering the number 

 of trunks of ferns, Caulopteris, found in the Coal Measures of Illinois, if the 

 coal flora represented in the concretions did not indicate a proportion of fruit- 

 ing branches nearly as marked as it would be in collecting ferns of our time in 

 a given area. 



It is peculiar that, though evidently belonging to herbaceous species of 

 fern, there has not as yet been found any fructification of the genus Neuropteris. 

 Leaves of Neuropteris hirsuta are the most abundant and the best preserved of 

 all the remains of fossil plants in the nodules of Mazon creek, and yet neither 

 here, nor anywhere else in our Coal Measures, has anything been discovered 

 which might be considered, beyond a doubt, as its fructification. For the in- 

 tumescence of veins or veinlets, often remarked on the surface of the leaflets of 

 this and other species of Neuropteris, and doubtfully considered as produced by 

 groups of fructification placed underneath, seems rather to be the result of some 

 casualty of maceration of the leaves. A mode of fructification of this kind 

 does not agree with that of ferns, and is rather comparable to the Osmundacece 



