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 are 

 many more which we cannot explain without supposing that the coal must 

 at the time of the disruption have been moulded and 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 Rhine- 

 Prussia and Silesia that different seams are distinctly formed of different 

 plants, sometimes Sigillaria and Lepidodendron, at others Coniferee, 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-swaraps 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 which 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 Aviciilo-pecten papyraceus, Goniatites Listeri, Oftkoceras, aud 

 Lingula — in Derbyshire, North Staffordshire, and in North Wales. 

 Again, they occur very similarly in South "Wales at Merthyr aud Nant- 

 y-glo, and further west in the Kilkenny coal-field. I have devoted, at in- 

 tervals, several days 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 high 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 



