SALTER — A CHRISTMAS LECTURE ON COAL. 
123 
The Acliantites of the Old Reel Sandstone, mentioned last month, 
will be figured, and full descriptions given of it by the officers of the 
Irish Geological Survey ; it is only, therefore, needful to give a sketch 
Fig. 3.— Osmunda regalis, living at Klllai-uey. Fig. 4. — Adiantites Hibemicus, fossil in 
To show the terminal fructificatfon of Kilkenny. To show the lateral spikes 
the Mving fern. of fructification in the fossil. 
figure of it here, especially as it does not actually belong to the coal, 
though the same genus is found there. We must now pass on from 
the ferns, and speak of the cylindrical stems so common in the coal. 
The other plants of the coal, which strike us most, are the fluted 
stems called Sigillaria. They abound in all the shales, with every 
kind of varying proportion in the patterns, which nevertheless is 
of a regular and definite kind. It consists of longitudinal flutings, 
generally in right lines, sometimes a little zigzag; and on the surface of 
the flutings are scars, either round or somewhat kidney-shaped, or hex- 
agonal — or even double ovals — or purse -shaped, narrower above than 
below, and always with a couple of dots in them, which ai'e the marks 
of the vessels that supplied the leaves. For the scars are the bases 
of the leaves, which are seldom found ; they are of a long shape, vnth 
a rib down the middle. The stems varj^ from a few inches broad to 
three feet in circumference, and specimens have been found that must 
once have been sixty feet long. They are generally quite flat in the 
shale, and often broken to pieces ; and they are, most generally, 
covered with a coat of coal. The scars outside the coal-envelope are 
not quite the same as those which show within, but pretty nearly so. 
Our figure shows this (Fig. 5) . 
