corda's extinct flora. 125 



these. It seems to have been a very small and delicate Fern, with 

 its capsules grouped in fours, enclosed in a spherical indusium which 

 opened by four valves. 



13. Schizceacece. — Under this head is described a very beautiful 

 fossil Fern, discovered in the coal-mines of Nachod in Bohemia, 

 with its fructification in an extraordinary state of preservation. It 

 closely resembles the existing genus Mohria, but is well distinguished 

 by the structure of the ring of its capsules, which here consists of 

 four or five rows of cells, in Mohria of a single row. 



14. Marattiacece, — Our author refers to this tribe the remarkable 

 fossils known under the name of ' Psarolites,' forming the genus Psa- 

 ronius of Cotta ; and he enters into a minute and elaborate exami- 

 nation of their structure, comparing it in detail with that of the 

 recent Marattiaceae, especially of Angiopteris, and showing the close 

 aflJnity that exists between them. The most important points of 

 internal structure in which the Marattiaceae differ from ordinary 

 Ferns, are, that the fibro-vascular bundles of the stem are irregular 

 in form, not arranged in a circle, but scattered without any appa- 

 rent order through the cellular tissue ; that the vessels of each 

 bundle are not enclosed in a woody sheath composed of hard and 

 dark-coloured fibrous tissue, nor is the stem itself coated with a 

 rind of such hardened tissue ; and that the vessels of the roots are so 

 arranged as to present in a transverse section the appearance of a 

 star. In all these peculiarities Angiopteris arjd Marattia agree with 

 the fossil Psaronii. But no recent Marattiaceae, as far as is hitherto 

 known, have their stems so densely clothed with a compact mass of 

 matted roots, as is the case in most of the Psarolites. 



In the present work, not less than twenty-six supposed species of 

 Psaronius are described and figured, all of them from Bohemia and 

 Saxony, where they occur either in the " Rothe-todte-liegende " or 

 the coal-formation, and sometimes (in a rolled state) in alluvial de- 

 posits. The first two species, Psaronius carhonifer and P. mus(B- 

 formis, are extremely different in appearance from most of the others, 

 so that no one would have supposed them to belong to the same 

 genus; the external mass of roots is wanting, and the vascular 

 bundles of the stem are arranged with a regularity which is not ob- 

 servable in any other Psarolites ; in fact, the peculiar arrangement of 

 these bundles has caused the second species to be taken for a plant 

 of the Banana tribe. As the structure of the tissues is not visible 

 in either species, the place assigned by Corda to these fossils can 

 scarcely be regarded as definitive. The third species, P. arenaceus 

 (which as well as the two preceding and the two following was 

 discovered in the coal-sandstone of Radnitz in Bohemia), is likewise 

 destitute of air-roots, and has two vertical rows of leaf-scars on each 

 side of its compressed stem; but the appearance of its vascular 

 bundles is somewhat more like that seen in ordinary Psarolites. /*. 

 pulchcr exhibits a structure in some degree intermediate between 

 the preceding and the better-known forms ; and tlie fifth species, 

 P. Radnicensis, likewise found in the sandstone of the coal-formation 

 at lladnitz, has all the characteristic peculiarities of the genus. 



