458 PALEONTOLOGY OF ILLINOIS. 



These specimens are generally flattened to less than one inch in thickness, as 

 if the stem had been of a soft texture. Generally the coat of superposed radi- 

 cles is transformed into a pellicle of coal and these are marked on their sur- 

 face by very thin parallel striae, perceptible only with a strong glass. This 

 coating of radicles upon the stem of a fern has nothing peculiar in it, as some 

 fern trees of our time show the same kind of conformation. One species, 

 Polypodium armatum, Swartz, from Brazil, is figured in Sternberg's Vers., vol. 

 i, pi. E. But from the Coal Measures we have as yet nothing anala^ous to this 

 species. 



The beautiful stem represented, figs. 1 and 2, is from the shale of Morris, 

 and belongs to Mr. Jos. Even, who kindly furnished me with splendid photo- 

 graphs of it. 



CAULOPTERIS ACANTOPHORA, Sp. nov. 



PI. xxvi, tig. 3 and 4. 



THE species is represented by numerous specimens, some of 

 them of large size, all of the same appearance. Their sur- 

 face, either naked or coated with a pellicle of thin coaly mat- 

 ter, is marked by irregular elevated points, placed without 

 regular order, evidently the basilar scars of spines, with which 

 the branches or stems were covered. On the large specimens 

 no trace of branch scars was discernible, but the oval line, 

 marked fig. 3, running parallel to a broad depression seen at 

 the corner of the figure. It is a kind of deep convexity in the 

 shale, with smooth, irregular borders, resembling rather the 

 impression left by the sides of a nodule than a branch scar. 



Fig. 4 represents a branch of this species, apparently at least, for it has the 

 same kind of cicatrices exactly on the surface, and still bears on its borders 

 some of the hooked spines by which they are produced. The branch is atten- 

 uated into a conical point of attachment which does not resemble that of a 

 branch of Caulopteris, and is also marked in the middle by a scar which, per 

 contra, has the form of the branch scars of a fern. These specimens, all flat- 

 tened, are therefore probably only referable to this genus. 



It abounds, like the former species, at Colchester, and is also found at Morris. 



