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XVII. — On the Fossil Flora of the Radstock Series of the Somerset and Bristol 

 Coal Field (Upper Coal Measures). Part I. By Eobert Kidston, 

 F.B.S.E., F.G.S. (Plates XVIII.-XXVIII.) 



(Bead April 4, 1887.) 



My attention for the last few years having been specially directed to the 

 vertical distribution of the Carboniferous Fossil Flora, it is my intention to 

 publish a series of papers dealing with this subject. 



While carrying on these investigations it has been necessary, in addition to 

 visiting public and private collections, to visit several of the coal fields for the 

 purpose of collecting specimens, as in almost no case have the smaller and less 

 attractive species been secured, and, as a rule, only what strikes the ordinary 

 collector as being "a fine specimen" is preserved, to the exclusion of many less 

 striking but often more valuable examples. Hence our public collections, and, 

 with few exceptions, also our private collections, give a very imperfect idea 

 of the richness of the flora of the Carboniferous Formation of Britain. 



For the last four years I have annually paid a visit to the Radstock portion 

 of the Somerset and Bristol Coal Field, with the object of collecting and 

 examining the fossil flora of this area, from which were obtained several of the 

 species described by Br.ongnia.rt, and which is probably richer in fossil plants 

 than any other coal field in Britain, — not only in the number of species it con- 

 tains, but also in their excellent state of preservation. 



A most important point in an investigation of this nature is to have the 

 position of the beds from which the specimens have been derived accurately 

 determined. In regard to the Radstock series of the Somerset and Bristol 

 Coal Field, this qualification is amply fulfilled, making this area peculiarly suit- 

 able as a starting point for investigations in the vertical distribution of the 

 British Carboniferous flora. 



The geology of the Somerset and Bristol Coal Field, and especially the 

 geology of the Radstock portion, has been fully worked out by several 

 geologists, but it may not be out of place to introduce here a short geological 

 sketch of this district, especially referring to the Radstock Series, from which 

 all the specimens mentioned in the following list have been collected. 



The Somerset and Bristol Coal Field extends from Cromhall in Gloucester- 

 shire to Frome in Somerset, and from Bath in the east to Nailsea and Clevedon 

 on the west. 



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