The Royal Society, London. 39 



Berichte gelehrter Gesellschaften. 



The Royal Society, London, 2G/1. lH9y. 



„On theStructure andAffinities of Fossil Plants fr om 

 the Pala^ozoic Rocks. IK. On Medullosa anglica, a new 

 Representative oftlie Cy cadof ilices." By D.H.Scott, 

 M. A., Pli. D., F. R. S., Hon. Keeper of the Jodrell Laboratory, 

 Royal Gardens, Kew. [Received December 21, 1898.] 



(Abstract.) 



The existence of a group of fossil plauts, combining in their 

 Organisation certain characters of the Ferns and the Cycads, has 

 been recognised, of late years, by several palißobotanists, as, for 

 example, by the late Professor W. C. WilJiamson, Count Solms- 

 L a n b a c h , Mr. S e w a r d , and the author. The convenient name, 

 Cycadofdices, has recently been proposed by Professor Potonie 

 to designate the group in question, which now includes several, 

 somewhat heterogeneous, genera, among which Lyginodendron, 

 Heterangiam, and Medullosa may be mentioned. 



Several species of the genus Medullosa (foundet in 1832 by 

 Cotta) have already been described, from the Permian and Upper 

 Coalmeasures of the Continent. They agree in the extraordinarily 

 complex structure of the stem, which, as shown by Zeiller and 

 Solms-Laubach, resembles in the ground plan of its Organisation, 

 that of a highly differentiated Fern, of the usual polystelic type, but 

 with the addition of a zone of secondary wood and hast, sometinies 

 reaching an immense thickness, developed around each stele. Tiie 

 mature stem thus acquired a Cycad-like character. The structure, 

 however, has been extremely difficult to the Interpret owing to the 

 comparative rarity and incoraplete character of the specimens hitherto 

 known. 



No stem of a Medullosa has hitherto been recorded from this 

 country, though specimens of Myeloxylon, now known to have been 

 the petioles of Medidlosa, are frequent in the calcareous nodules of 

 the Lower Coal-measures. 



The author has recently had the opportunity of investigating 

 several excellent specimens of a new species of Medidlosa from the 

 Ganister Beds of Lancashire. These fossils are of special interest 

 on several grounds ; the are considerably more ancient than any 

 members of the genus previously described, they are the tirst 

 English specimens recorded, they are preserved in a more complete 

 and perfect form than any others at present known, and laslly, 

 the greater simplicity of their structure causes the essential clia- 

 racters of the genus to stand out with greater clearness than in the 

 more complex species. The specimens were discovered by ]\Ir. 

 G. Wild and Mr. J. Lomax, in materiai from the Hough Hill 

 Colliery, Stalybridge. The sections have been cut, with the greatest 

 skill and success, by Mr. Lomax, and are very numerous, abont 



