94 Correspondence — Mr. R. Etheridge. 



DR. WHEELTON HIND'S CAEBONIFEROUS LAMELLIBRANCHIATA.— 

 PART I. INTRODUCTION (PAL^ONTOGRAPHICAL VOLUME, 1896). 



Sir, — Under the heading of " General Sequence of the Carbon- 

 iferous Rocks," which embraces analyses or divisions of some of 

 the coalfields in Britain, reference is made to the succession of the 

 rocks in the Coal-measures in Somersetshire, or the southern part 

 of the Bristol Coalfield. Under the general terra Coal-measures, in 

 the division " Uppkr," are placed — (1) TheEadstock and Farringdon 

 Series ; (2) The New Rock and Vobster Series : both these are classed 

 as belonging to the Upper Group of Coals. 



The Radstock and Farringdon Series are undoubtedly membei'S 

 of the Upper Coal-measures, and of the uppermost division 

 in Somersetshire; but the Neic Rock and Vohster Series, or coals, 

 are in the lowest part of the Loieer Coal-measures, — the two series 

 being separated by nearly 2000 feet of the well-known ''Pennant 

 Sandstone," so that the term Upper is here most misleading. 

 Between the lines Eadstock and Farringdon Series, should be 

 inserted the "Middle or Pennant Seriks, or Sandstones" (2000 feet 

 thick). The term "Millstone Grit" has no value here, unless the 

 New Rock and Vohster Series (coals) are inserted below the Pennant 

 and above the Millstone Grit, in the Somersetshire portion of the 

 Bristol Coalfield, the northern and southern areas forming one con- 

 tinuous field. We can hardly understand how the northern and 

 important division of the Bristol and Somerset Coalfield was omitted 

 in the sequence. The entire basin is 26 miles from north to south, 

 and 8 to 10 miles from west to east, but continuous and almost 

 unbroken, the sequence being the same in either case, the Carbon- 

 iferous Limestones and coal shales being highly fossiliferous. The 

 Bristol Coalfield is the most typical and perfect in stratigraphical 

 succession of any of the coalfields in Britain. I draw Dr. Wheelton 

 Hind's attention to this very important omission in order that he 

 may make his monograph upon the fossils of the British Carboniferous 

 rocks for the Palasontographical Society as complete and accurate as 

 possible, and that he may be induced to look carefully into the 

 true succession of the different areas that will come under his 

 examination. E. Etheridge. 



(D:BXTTrj^iRir. 



DAVID ROBERTSON, LL.D., F.L.S., F.G.S. 



BoKN November 28, 1806. Died Notembeb, 20, 1896. 



DiviD Robertson, once upon a time the little herd-boy of a 

 Lanarkshire moorland farm, by -and -by the successful Glasgow 

 merchant, and then for thirty or forty years the keen, shrewd, 

 patient observer, bent on the acquisition and furtherance of " natural 

 knowledge," has passed away, after a life that has still been " too 

 short for friendship," although so greatly prolonged. He was born 

 in 1806, November 28 of the Old Style ; he died in 1896, 

 November 20 of the New Style, and therefore just within three 



