LcK(ii]oroiix.] oJo [Jan. 5, 



to Stems, and, therefore the relation of many of them to the plants which 

 they represent prevents their reference to original types, and forces, for their 

 description, an artificial classification which the discovery of a single 

 specimen may overthrow. Hence it happens that, in tiie pursuit of his 

 researches to recognize the specific characters or even the more distant 

 rehitions of the vegetable fragments, the paleontologist is forced to look for 

 and to compare a large number of specimens before he is able to fi.\ their 

 references. The subdivisions of the leaves or fronds of ferns, the pinnae 

 and pinnules, have not between the same spacies that kind of likeness or 

 affinity of shape remarked between the leaves of dicotyledonous plants. 

 The modilicalions of form are not only extremely numerou.s, but present 

 such an anomalous diversity, that botanists unacquainted with this section 

 of natural history could often suppose no generic relation between some 

 of the leaflets which represent the same species. One of the most common 

 ferns of the middle coal measures, a Neuropteris, for instance, is nearly 

 always found in detached, fine, large, cordate-lanceolate leaflets, which 

 sometimes measure four to five inches in length and two or three inches in 

 diameter. Home small round or broadly oval pinnules arc generally found 

 mixed with those large leaves ; they are not even half an incli in diameter ; 

 and though they have a similar character of nervation, the diflerence in 

 shape and size is so marked that they were of course described under a 

 difTcrenl specific name. Lindley and Hulton were the first to suppose, 

 from llieir coincidence of local distribution, that they might possibly repre- 

 sent parts of the same plant. Since then, and long afterwards, large branches 

 of fronds have been discovered in this country wuth the two forms of leaves 

 attaclied to the same pedicel, the large leaves being borne upon a short 

 stalk, witli two small leaflets attached to their base. A numl)er of cases ot 

 the same kind might be mentioned ; but this one is sufficient, and I quote 

 it not merely to show how great are the difflculiics encountered by the 

 botanist in the study of coal plants and what persistence it demands, but 

 to prove that the discoveries made iu the coal flora of this continent ren- 

 der now to European pale:)ntologists the same amount of assistance that 

 we have received from their works iu former times. 



Tlie remains of coal plants, gcnerall}' pleasant to the eye by their grace- 

 ful sliape, and some of them of very peculiar forms, widely apart from 

 those which are generally observable in the vegetation of our time, could 

 not but, as wonderful productions of nature, excite the interest of the first 

 investigators of the carboniferous measures of Penn.sylvania. Already 

 in 1818, Steinhauer had published in the Transactions of the American 

 Philosophical Society his Fossil reliquia, where remains of plants now re- 

 ferable to Galamites, Lepidiidi'iulron, Ulodendron, Artisia, Sigillaria, and 

 ' Sligmaria, nre figured and described under the collective name of Phyto- 

 lithes. He does not represent any kind of fern ; but he mentions in the in- 

 troduction that most of the specimens of fossil plants from the carboniferous 

 are lilices (ferns). After him, in 1820, Granger mentions without doscrip 

 tions a fevv specimens of coal plants from Zanesville, Oluo. From that time 



