INTRODUCTION. iii 



ences in the Index itself threw but little light upon the subject. I have endeavoured 

 as far as possible to make this task easy to such students as may consult what I 

 have written. A second feature is equally important. My entire Cabinet of 

 sections of these Carboniferous plants, of which a very elaborate descriptive cata- 

 logue is already prepared, is destined to find its ultimate home in the Botanical 

 Museum of the Owens College, where it will be accessible to any palaeontologist 

 who may desire to consult it. In the catalogue referred to, the description of each 

 specimen embodies a statement as to what, in my opinion, that specimen teaches or 

 proves. The result will be that, whether those who may follow me in these 

 researches agree with my views or feel compelled to reject them, they can them- 

 selves examine the specimens upon which those views were based. In order to 

 make such references easy, so far as the present work is concerned, the Cabinet 

 number of each specimen figured is attached to the notice of each figure in the 

 Index to the Plates. The cases where no such numbers are recorded belong 

 to specimens not in my cabinet. Such examples, however, are extremely few, 

 nearly all the specimens figured being in my own possession. 



Stigmariae, which are mere casts or impressions, no portion of their internal 

 organisation being preserved, are widely, and often abundantly, diffused through the 

 entire series of the Upper Carboniferous Rocks of Lancashire and Yorkshire down 

 to the Millstone Grit. But the beds, from which specimens, not only of Stigmaria, 

 but of numerous other plants having their internal structures exquisitely preserved 

 have been mainly derived, are the thin, lowermost coal-seams of the Ganister series. 

 These plants occur in nodules, of various diameters from a foot downwards, which 

 are embedded in the substance of the coal. In some localities these nodules 

 are so numerous as to make the working of the coal-seam unprofitable ; a fact 

 unfortunate for the palaeontologist, since such commercially unprofitable collieries 

 are liable to be closed. So far as the Lancashire seams in which these plant-bearing 

 nodules occur are concerned, an excellent summary of them will be found in Mr. 

 Binney's ' Memoir on Calamites and Calamodendron.' 1 For the following detailed 

 section of the corresponding series of deposits in the Halifax district I am 

 indebted to my friend J. W. Davis, Esq., F.G.S., of Chevinedge, Halifax. 2 



1 Palaeontographical Society's volume for 1867. 



2 It is fortunate for geological science that similar deposits have now been discovered at three 

 separate localities on the Continent. One of these is at Pith Vollmond, in Westphalia, where my friend, 

 Count de Solms, tells me he finds in great abundance Lepidodendron selaginoides, Lyginodendron 

 Oldhamium, and Rachiopteris aspera, as well as examples of Amyelon radicans and some other well- 

 known Yorkshire and Lancashire forms. One of the remaining two is in the Banat, in South Hungary, 

 and the other in Moravia. In all these places the deposits appear to be of the same age as those of 

 Yorkshire and Lancashire, each being also overlain by a bed containing the marine Aviculopecten, as 

 in our Ganister series ; it is from these shells, along with other mollusks, that the lime, which has 

 played so important a part in the preservation of our plants, has been derived. 



