TRANSACTIONS OF SECTION K. 493 



Joint Meefing with Section C. 



The following Report and Paper were received : — 



Report of the Co-nimittee for Excavating Critical Sections in the Old 

 Red Sanchlone Rocks at RJiynie, Aberd'eenshire. — See Repoiis, 

 p. 206. 



2. On Ehynia Gwynne-Vaughani. 

 By Dr. E. Kidston, F.R.S., and Professor W. H. Lang, F.R.S. 



At Rhynie, in Aberdeenshire, well-preeerved silicified plant-remains occur 

 in a chert bed, not younger than the Middle Old Red Sandstone. There are 

 two vascular plants — Rhynia Gwynne-Vaughani and Asteroxylon Maclciei, 

 discovered by Dr. Mackie. The present paper deals only with lihynia, an 

 illustrated account of which is in course of publication by the Royal Society of 

 Edinburgh. Asteroxylon is still under investigation. 



The plants of Ehynia Gwynne-Vaughani grew closely crowded together, and 

 their remains formed a peat. The plant was rootless and leafless, consisting 

 entirely of a system of cylindrical stems. The rhizome was fixed in the peat 

 by rhizoids and tapering aerial stems grew up from it. The plant probably 

 attained a height of 8 inches or more, and the stems range in diameter from 

 6 mm. to under 1 mm. The stems bore small hemispherical projections. In 

 place of some of these projections lateral branches developed. Dichotomous 

 branching also occurred sparingly. 



The aerial stems had a thick-walled epidermis with stomata ; a cortex, distin- 

 guished into a narrow zone of outer cortex and a broad inner cortex ; and a 

 simple central cylinder, consisting of a strand of tracheides surrounded by 

 phloem. 



Large cylindrical sporangia, containing numerous spores, were found in the 

 peat. They were evidently borne terminally on some of the leafless aerial stems. 



Rhynia, and eome of the specimens of Psilophyton princeps figured by 

 Dawson, cannot be placed in any of the main classes of the Vascular Cryptogams 

 (Filicales, Lycopodiales, Equisetales, Sphenophyllales, Peilotales) at present 

 defined. A new class, for which the name Psilophytales is proposed, is there- 

 fore founded for their reception. This is characterised by the sporangia being 

 borne at the ends of branches without any relation to leavee or leaf-like organs. 



THURSDAY, SEPTEMBER 7. 



The following business was transacted : — 

 1. On Leaf Architecture.'^ By Professor F. O. Bower, F.R.S. 



2. Discussion on the Utilisation and Improvonent of Waste Lands. 

 Opened by Professor F. W. Oliver, F.R.S. 



The present collection of short papers dealing with the general subject of 

 Waste Lands were delivered before the Botanical Section (K) of the British 

 Association at the request of the President of the Section. The question of the 

 utilisation and improvement of Waste Lands was one of a large number which 

 had corne under the notice of the Sectional Committee. Several members of 

 the Section having had practical experience — botanical, geological, or economic — 

 of ground of this kind, it was decided that a sufficient number of commu- 

 nications should be arranged with a view to forming the basis of a discussion 



' Published in Trans. R. S. Edin., 1916, vol. iii., part iii., p. 21. 



