"Vol. 69.] THE PEMBROKESHIRE COALFIELD. 275 



■Coal Measures, and do not belong to the Transition Series. The 

 Lower Coal Series of Pembrokeshire has also been proved to belong 

 to the Middle Coal Measures ; while the Settlings Beds, and perhaps 

 the Falling-Cliff Beds as well, have also been shown to lie probably 

 at a higher horizon than the Lower Coal Series as developed farther 

 east along the Saundersfoot coast, and possibly higher than the 

 Timber Vein Group. 



Until more plants have been obtained from the so-called ' Mill- 

 stone Grit ' of Pembrokeshire, it is impossible to fix definitely the 

 horizon of this group from the palaeobotanical evidence. However, 

 "the so-called 'Millstone Grit' beds of Monkstone Point have been 

 shown to belong probably to the Middle Coal Measures. 



It has also been shown that there are considerable differences in 

 the occurrence of the species in the Pembrokeshire Coalfield, when 

 they are compared with those which have been recorded from the 

 main portion of the South Wales Coalfield. In this connexion it has 

 been indicated that thirty-two species have been added to our lists 

 ■of the flora of the Middle Coal Measures of South Wales. 



VII. Bibliography. 



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Arber, E. A. N. (1910). ' On the Fossil Flora of the Southern Portion of the 



Yorkshire Coalfield in North Derbyshire & Nottinghamshire ' Proc. Yorks. 



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 Brown, T. F. (1874). 'The South Wales Coalfield' Trans. N. Engl. Inst. Min. 



Eng. vol. xxiii, p. 210. 

 De La. Beche, Sir Henry T. (1826). ' On the Geology of Southern Pembrokeshire ' 



Trans. G. S. ser. 2, vol. ii, p. 1. 

 Id. (1846). ' On the Formation of the Bocks of South Wales & South- Western 



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 •Jackson, J. W. (1911). 'Remarks on some Palceoxyris from the Middle Coal- 



Measures of Lancashire ' Lancashire Naturalist (January 1911) p. 331. 

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Trans. Roy. Soc. Edinb. vol. xxxvii, pt. 3, p. 565. 

 -Mackie, S. J. (1865-67). Geol. & Nat. Hist. Repertory, vol. i, pp. 79-80. 

 Martin, E. (1806). 'Description of the Mineral Basin in the Counties of Mon- 

 mouth, Glamorgan, Brecon, Carmarthen, & Pembroke ' Phil. Trans. Roy. Soc. 



vol. xcvi, p. 342. 

 JMoysey, L. (1910). ' On Palceoxyris & other Allied Fossils from the Derbyshire 



& Nottinghamshire Coalfield ' Q. J. G. S. vol. lxvi, p. 329. 

 Murchison, Sir Roderick 1. (1836). 'On the Geological Structure of Pembroke- 

 shire . . . . ' Proc. G. S. vol. ii, p. 226. 

 Owen, G. (1796). 'A History of Pembrokeshire .... with additions .... by John 



Lewis . . . . ' Cambrian Register, vol. ii, pp. 53-230 (' Fuel' Chap. 10). 

 Ramsay, Sir Andrew C. (1846). 'On the Denudation of South Wales & the 



Adjacent Counties of England ' Mem. Geol. Surv. vol. i, p. 297. 

 Renault, B. (1888-90). 'Etudes sur le Terrain Houiller de Commentry' vol. ii 



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 Id. (1907). ' The Geology of the South Wales Coalfield, pt. vii— The Country 



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