1845.] BUNBURY ON FOSSIL FERNS. 85 



and as the specimen figured and described by that author is still 

 more incomplete than Mr. Lyell's, so that one can hardly either 

 distinguish or identify them with certainty, I think it safer to con- 

 sider them provisionally as the same species. Our Frostburg plant 

 will therefore stand as 



3. Dan^eites asplenioides var. major. 



The frond appears to be bipinnatc, and if a flattened stem (appa- 

 rently the stipes of a fern) which occurs in the same slab belonged 

 to this plant, it was of large size, for the stem in question, in its 

 compressed state, measures an inch and a half across. The pinnules 

 are closely set, oblique, rounded at the end, slightly combined at 

 the base, but neither dilated nor decurrent, of an oblong or broadly 

 linear form, flat, or scarcely convex, about ^ths of an inch long, and 

 about half as much in breadth. Veins very indistinctly marked, 

 but seemingly nearly perpendicular to the margin. The fructiferous 

 pinnules (which are on a separate pinna, but which I believe to be- 

 long to the same species) are rather larger than the others, but of 

 the same shape; the fructification has the appearance of linear 

 masses, placed parallel and nearly contiguous to one another, per- 

 pendicular to the midrib, and extending from it quite to the margin. 

 Its general resemblance to the fructification of the curious genus 

 Dancea is very striking, but I am not quite satisfied that it is really 

 of the same nature; for on a close examination one may detect 

 traces of round spots ; and perhaps the apparently linear masses 

 may have been made up by the aggregation of numerous round 

 ones. 



Goppert has not figured the barren pinnules of his Danceites aS' 

 plenioides; the fertile ones represented in his plate differ from those 

 of our plant merely in being considerably smaller, and perhaps ra- 

 ther narrower in proportion. 



It is to be observed, that although the appearances of fructifica- 

 tion in all these three plants are clear and unequivocal, yet in the 

 first two species at least, it is invariably the upper surface of the 

 frond that is exhibited to our view ; now, in all recent ferns, the 

 fructification is situated on the under surface ; we must therefore 

 suppose that what we see in these specimens are not the masses of 

 capsules themselves, but the impressions of them, as it were, stamped 

 through the substance of the leaves by the pressure to which they 

 were subjected in the process of fossilization. This appears to be 

 most usually the case with those fossil ferns which occur in a fertile 

 state, and may be one reason why it is more difficult to determine 

 with precision the characters of the fructification in these than in 

 the recent plants. Dr. Lindley long ago observed*, that fossil ferns 

 are much more often found with their upper than with their lower 

 surface exposed to view, the lower seeming to adhere more closely 

 to the matrix; and Professor Goppertf, in his curious experiments 



* Fossil Flora, text to t. 83. f Syst. Filicum FossUiura, p. 293. 



