42 The Royal Society, Louclou. 



which the connection between leaf and stem has been at all satis- 

 factorily proved. 



In the structure of tlie petioles, and of" the roots, in the secon- 

 dary tissues, and in the secretory canals, which occur throughout 

 the plant, there are clear points of agreeraent with Cycads, though 

 the primary structure of the stem was that of a Fern. The affinities 

 in the latter direction came out more clearly in Medullosa anglica 

 than in any of the other species as a present known. 



The habit of the leaves, if as appear likely, they were of the 

 Alethojjteris type, must have been fern-like, but that in itself, as the 

 familiär example of Stangeria teaches, is a consistent with Cycadaceous 

 as with Filicinean affinities. 



While Medullosa thus combines, in a striking manner, the 

 characters of Ferns and Cycads, the author is not disposed to re- 

 gard it as having lain very near the direct line of descent of the 

 latter group. It is more probable, as Count Solms-Laubach 

 has suggested, that the Medullosae represent a divergent brauch, 

 which has left no descendants among existing Vegetation. 



Medidlosa anglica, sp. nov. 



Stem vertical, clothed by large, spirally arranged decurrent 

 leaf-bases, perhaps cast off in old steras. External surface of leaf- 

 bases longitudinally striata. 



Vascular System of stem consisting of a few (usually thvee) 

 uniform steles, somewhat elongated and lobed as seen in transverse 

 section. Star-rings absent. Interior of each stele wholly occupied 

 by primary wood. 



Secondary wood and bast of moderate thickness, developed on 

 all sides of the steles, Tracheides usually with bordered pits. 



Leaf-traces concentric on leaving the steles, branching and be- 

 coming collateral in traversing the cortex. 



Leaf-bases and petioles with the structure of Myeloxylon 

 Landriotii Ren. 



Leaves highly Compound. 



Gum-canals abundant in the petioles and leaf-bases, and in the 

 cortex, and around the steles of the stem. 



Adventitious roots borne in vertical series, triarch, with secondary 

 wood and bast, and periderm. 



Stem with leaf-bases, about 7 — 8 cm. in mean diameter. 



Petioles about 2.5 — 4 cm. in diameter at base, dirainishing to 

 about 1 mm. in the ultimate branches of the rachis. 



Leaflets about 3 mm. wide. 



Roots reaching 12 mm. in diameter. 



Locality: Hough Hill Colliery, Stalybridge, Lancashire. 



Horizon : Lower Coal-measures. 



Found by Messrs. G. Wild and J. Lomax, 1892—98. 



Aiiuales d«» la Soci^te liiineenne de Lyon. Annee 1898. Nouvelle serie. 



T. XLV. 8». XI, '216 pp. Paris (J. B. Bailliere & tils) 1899. 

 Ganoug, W. F., The Society for Plant Morphology and Physiology — Columbia 



Meeting. (The Botanical Gazette. Vol. XXVII. 1899. No. 2. p. 118—130.) 



