56 "SLU. D. D.VYTE5 0^ THE ECOLOGY OF [toL IxiYll, 



the former seam lying 600 feet above the Six-Foot Seam. Argil- 

 laceous shales are found above that seam for a distance of about 

 10 feet, and immediately above these the shale is siliceous. The 

 shales were obtained from north, south, east, and west of the shaft. 

 Both kinds of shales were obtained fi-oni each area at a point about 

 3-30 yards from the shaft. Of the Equisetales, AsferophifUites 

 proved to be more numerous than Calamites, although the 

 latter were sufficiently numerous. Sphenophyllales are fairly well 

 represented here for the iii-st time, as it will be noticed that the 

 underlying horizons yield no evidence of their presence, excepting 

 the Middle Yard Seam, and even there they were very rarely found. 

 Lycopodiales are still abundant, JLepidodendron alone representing 

 a fifth of the whole of the plants recorded. Both rode iidroa was 

 found only in this seam. Filicales and Pteridosperms show 

 Jfcc/'ioj) ten's dominating the other genem of ferns or fernlike 

 plants for the first time. Specimens of the rachis of ferns are 

 also very much in evidence. Cordaite-leaves, too, are fi'equently 

 found. 



Lycopodiales for the second time show their predominance over 

 the other classes of plants. 



The Abergorky Seam (Table VIII cV- fig. 9, pp. 45-49).— 

 This seam hes at a depth of 360 feet at the Blaenclydach ColHeiw, 

 Clydach A'ale. The shales were obtained from an. extensive area, 

 in directions south-east and west respectively from the shaft. 

 The shales examined were obtained from beds between 5 and 12 

 feet above the coal-seam ; they were unifonnly coarse-srrained and 

 siliceous. Of the Equisetales, specimens of AsterajjliyUites were 

 very common throughout, numl^ering slightly more than half the 

 whole of the plant-remains from the other classes. Spheno- 

 phyllales are again very rare, and Lycopodiales all but absent. 

 The ferns or fernlike j)l^iits are somewhat scantx', y^europteris 

 dominating the other genera. Cordaite-leaves were found fairly 

 often. The Equisetales are very numerous, and exceed in number 

 aU the other classes of plants put together. 



The Xu.3 iihondda Seam (Table IX ^y fig. 10, pp. .30—51). — 

 The shales overlying this seam are invariably light in colour and 

 of fine textm'e. Blocks of shales were obtained near the shaft, 

 and also from a point 3000 yards distant. The dii-ection fi-om 

 Avhich the shales were obtained lies north-east of the Glamorgan 

 Colliery, Gilfach Goch : the seam is met with 299 feet down the 

 shaft, and overlies the Abergorky Seam, with a thickness of strata 

 of -59 feet between the two seams. The shales for examination were 

 obtained from 3 to 12 feet above the coal-seam, and were very 

 fossiliferous. 



Of the Equisetales Asteropliyllites occurred in abundance, and 

 were more numerous than any of the other plants related to this 

 class. Sphenophyllales were met with rather frequently, Lyco- 

 podiales were very rare. The ferns or fernlike plants were well 



