368 
THE GEOLOGIST. 
SO much on opposite sides of them, that whilst in some few cases we may be 
led to suspect their contemporaneity with the beds themselves, there arc 
many more which we cannot explain without supposing that the coal must 
at the time of the disruption have been moulded und squeezed in an almost 
plastic condition. In the determination of the plants of the coal much 
has been done, and the Newcastle names of Hutton and Witham have 
gained deserved honours in the cause. But much remains to be done by 
microscopic inquiry and by the observation in the pits of the plants which 
accompany particular seams. Goppert tells us of certain coals of Ehine- 
Prussia and Silesia that different seams are distinctly formed of different 
plants, sometimes Sigillaria and Lepidodendron, at others Coniferae, and 
in many Stigmaria being chiefly prominent. May we not by degrees con- 
nect the peculiar and perhaps varying character of seams with the plants 
of which they are formed, and may we not advance to a much nearer per- 
ception of the true character of those wondrous primeval forests? And 
here I would remind you that whilst some of our guides in coal-geology 
incline to the opinion of a marine origin for their plants, thus bringing 
them into natural contact with the fishes and the probably marine shells 
often found in the shales, others insist on a terrestrial vegetation, and a 
third on that of lagoons or sea-swamps and bogs. The last few years 
have given more heavy arguments to those who insist on a lurid forest, 
however near to the water's level it may have been. We but recently 
knew that among these giant stems of Sigillaria the busy hum of flying 
insects and the merry chirp of the cricket were heard, that scorpions 
curled their ominous tails, that land shells crept slimily along, and that 
several genera and many species of reptiles either pursued their prey along 
the ground or climbed the trees, where hollow trunks have formed the 
casket to contain their remains. Here, then, is a goodly population to 
vivify the scene which only a few years ago was held to be almost wanting 
in all but vegetable life ; and when we consider the accidents which have, 
amid the great decomposition of organic matter, preserved to us these re- 
mains, generally enclosed in ironstone nodules, we must feel confident that 
coming years will have many an additional fact to disclose. Of the whole 
range of the carboniferous formation, perhaps the most interesting in 
several respects is the lower division. Many years ago. Professor Phillips 
described the peculiar group of unquestionably marine shells occurring in 
the roof ot the Halifax coals ; and my friend Mr. Binney has traced 
throughout the length of Lancashire several seams which are thus charac- 
terized, and M hich are invariably below the thick seams of the main coal- 
field. I have been greatly interested in hunting up the same group, — the 
well-known Aviculo-pecten papyraceus, Goniatites Listcri, Orthoceras, and 
Lingula — in Derbyshire, !North Staffordshire, and in jSTorth Wales. 
Again, they occur very similarly in South Wales at Merthyr and Nant- 
y-glo, and further west in the Kilkenny coal-field. I have devoted, at in- 
tervals, several daj'^s to the search for them in this coal-field, but hitherto 
unsuccessfully ; and whilst their occurrence lends great force to the proba- 
bility of the original unity and the subterranean connection of most of 
our coal-fields, their apparent absence in the Durham and Cumberland 
lower coals appears to indicate a peculiar difference in the conditions of 
deposition. The identification of distant seams, and of low as compared 
with higli measures, appeared on this evidence very feasible ; but Mr. 
Hull has not long since shown that caution is still needed, by announcing 
the occurrence of the same group in a higher seam in Lancashire. It is 
well known that the ironstone bands are among the most prolific sources 
of the objects of these studies, and I must, in conclusion, refer to the very 
