496 PALAEONTOLOGY OF ILLINOIS. 



of our time, which bear their fructifications either as separate racemes or on 

 peculiar divisions of their fronds. The fructifications of species of the genus 

 Odontopteris , so closely related to Neuropteris, are known for Odontopteris 

 Schlotheimii and 0. Reichiana, Gutb. The fertile pinnae, not yet found in con- 

 nection with sterile fronds, bear inflated, round leaflets resembling small blad- 

 ders, which have no relation whatever to the intumescence of veins considered 

 as the fructification of Neuropteris. 



Still more than their fructification, the rhizomas of ferns have hitherto been 

 unknown to palaeontologists, at least from the Coal Measures. Prof. Goppert 

 has given, in his FOBS. Farnkreuter, p. 91, tab. 33, fig. 1, the only fragment 

 which as yet has been published by European authors, as evidently belonging 

 to true rhizomas of the coal. In his Pal. Veg., Prof. Schimper has published, 

 under the name of JRhizomopteris, two fragments of plants, Selaginites Erdmanni, 

 Gein., and Selaginites uncinnatus, Lesqx., which, from the spiral development of 

 their branches, their ramifications and their scales, he considers as representing 

 small rhizoma of ferns rather than Lycopodiacew. I cannot agree, on this sub- 

 ject, with my celebrated friend. The plant published as Selaginites uncinnatus, 

 Lesqx., vol. ii, p. 446, pi. 41, of this Report, is too slender, and hag too slender 

 divisions to represent a rhizoma, even of a climbing fern. Its slender branches, 

 rather pinnately placed, are not more curved in spiral than they may be in 

 some of our species of Lycopodium, and the divisions are evidently pinnate, 

 like leaflets, and not scattered like hairs. The plant named Lycopodites Erd- 

 manni, by Geinitz, and which, as Prof. Schimper remarks, is different from 

 L. Erdmanni of Germ., has, like our Selaginites crassus, the ramification and 

 appearance of a Lycopodium, but from the examination of peculiar specimens 

 of the same species, seen by the author, it seems to belong to a rhizoma. Even 

 admitting that these two species represent climbing or aerial rhizomas, this 

 small proportion of organs of this kind, compared with the numerous species 

 of ferns known from the Coal Measures of Europe, would beunexplainable,but 

 for our American species. For the concretions of Mazon creek, and only 

 these from the whole extent of our Coal Measures, have furnished us numer- 

 ous specimens of eight species of these organs, some of them referable to sub- 

 terraneous rhizomas. It is, therefore, apparent that the organs of the ferns of 

 the Carboniferous epoch were the same, and in -the same proportion, as those of 

 our time, but, that some of these, like rhizomas and fruit-bearing fronds, have 

 been more generally destroyed in the shale on account of their soft texture. 



The inflated subcylindrical base of a species of Annularia and of a Lepido- 

 dendron are also two remarkable characters, not recognized as yet in the same 

 kind of plants of the Coal Measures, and which we owe still to the peculiar 

 preservation of vegetable remains in the concretions of Illinois. Species of 

 the genus Annularia may have been represented in the swamps of the Carbon- 

 iferous period by two kinds of leaves, according to their growth, either in water 



