"Vol. 69.] THE PEMBROKESHIRE COALFIELD. 279 



to west, might be applicable to a portion at least of the Millstone 

 •Grit of South Wales. 



Prof. Hull pointed out that the dissimilarity between the South 

 Wales Coalfield and those of the Midlands was amply to be accounted 

 for on the grounds that these coal-areas were never connected, but 

 were separated one from the other by a ridge of pre-Carbouiferous 

 rocks, extending from North Wales and Shropshire into the centre 

 and east of England under the Mesozoic formations. With regard 

 to the Lower Coal Measures of South Wales, they differed from the 

 succeeding Middle and Upper divisions, as they contained numerous 

 species of marine shells, such as Productus, Ortliis, Nautilus, etc. 

 These marine, though shallow- water, deposits were succeeded by 

 deposits of freshwater origin. 



The Author, in reply, thanked the Fellows present for their 

 kind reception of the paper. He pointed out that he only obtained 

 fossil plants from some of the highest beds of the so-called ' Millstone 

 Grit' : namely, from those at, and in the neighbourhood of, Monk- 

 stone Point ; Avith the principal exception of some from beds imme- 

 diately south of Waterwynch, which, however, give no definite 

 indication of the horizon of the beds in that district. He thought 

 that the evidence as to the horizon of the Monkstone-Point beds 

 would be seen more clearly when the paper was published. 



'Q. J. G. S. No. 274. 



