Reports & Proceedings — Geological Society of Glasgow. 285 



study of impression-material, of thin sections, and of macerated 

 material. 



The plant is most ahundant in the Lower Old Red of the 

 Kincardine-Forfar-Perth area, Avhere it is by far the commonest 

 fossil, especially in the shale-bands ; Parka is confined to the lower 

 two-thirds of the Caledonian Series. It is recorded from a few other 

 localities in Central Scotland, and also from the Upper Ludlow and 

 Lower Old Red of the ' Hereford ' area. 



The organism is shown to be a complete cellular thalloid plant, 

 agreeing generally in its vegetative structure with certain algae, but 

 differing from all known algse in the production of cuticularized 

 spores. The thallus is closely set with subcircular swellings (' discs '), 

 each enclosing a mass of simple spores (homosporous). An investing 

 layer, probably one cell thick, of relatively large cells surrounds the 

 smaller-celled 'parenchyma' of the thallus. The spore-masses are 

 individually enclosed by the latter tissue, but there is no indication 

 of a specialized sporangial wall. The growth of the plant is marginal 

 and indefinite, and mature spores are found in plants of all sizes — 

 that is, so far as observed, in all plants that are in a suitable state of 

 preservation. The structure described by previous writers as an 

 ' indusium ' is interpreted as the ' sole ' of the thallus in a more 

 or less detached condition. While the general structure and mode of 

 growth of the plant make it very difficult to place it higher than the 

 Thallophyta, it must be recognized that the organism is in some 

 respects unique. 



II. — Geological Society of Glasgow. 

 At a meeting on May 13, 1915, Professor J. W. Gregory read 

 a paper by himself and Dr. Home on " The Annan Red Sandstone 

 Series of Dumfriesshire ". He explained the different opinions that 

 had been held at various times with regard to the age of the red rocks 

 of South-Western Scotland. The identification of the age of these 

 rocks and their allocation to their true stratigraphical position had 

 been a matter of difficulty on account of the absence of fossils, with 

 the exception of reptile footprints such a*s those of Corncockle Moor, 

 and the fact that the rocks occurred in isolated areas. This had led 

 to their all being classed simply as " New Red iSandstones ", a loose 

 and unsatisfactory term. It had been found that, in the absence of 

 fossils, a study of the climatic and geographical conditions under 

 which a sedimentary rock had been formed frequently gave useful 

 guidance in identification, and this had proved to be the case in this 

 instance. The rocks of the Annan district can be traced across the 

 border and linked up with the St. Bees Sandstone, which is clearly of 

 Lower Triassic age. The Lochmaben, Dumfries, etc., Sandstones 

 agree rather with the Penrith Sandstone, which is Lower Permian, 

 and exhibit an absence of the Red Shale and angular material which 

 are so prominent in the Annan Series. The Annan Beds seem to have 

 been laid down in lagoons traversed by strong currents, while those 

 of Dumfries, etc., bear every mark of having been formed at a time 

 when the country was covered by one continuous sheet of desert sand, 



