Reports and Proceedings — Geological Society of London. 91 



II.— December 16, 1896.— Dr. Henry Hicks, F.K.S., President, 

 in the Chair. The following communications were read : — 



1. " On the Subdivisions of the Carboniferous Series in Great 

 Britain, and the True Position of the Beds mapped as the Yoredale 

 Series." By Dr. Wheelton Hind, F.R.C.S., F.G.S. 



In this paper the author gives a summary of our knowledge of 

 the local divisions of the Cai'boniferous system, and criticizes the 

 present classifications in vogue, laying special stress upon the local 

 variations in the lithological characters of the rocks, and summing up 

 to a large extent the fossil evidence which is available. He maintains 

 that the Yoredale Beds are largely the equivalents of the beds which 

 have elsewhere been referred to the Mountain Limestone Series, 

 though some local beds which have been included in the Yoredale 

 Series may rather be the equivalents of the Millstone Grit. He 

 advocates the abolition of the term " Yoredale Series " as applied to 

 a subdivision of the Carboniferous strata comparable in importance 

 to such divisions as Carboniferous Limestone and Millstone Grit, 

 but believes that the term may be usefully employed to denote the 

 changes in character of the beds due to causes which operated 

 locally, and to represent the Carboniferous Series as it occurs 

 in Wensleydale, Swaledale, Teesdale, and the upper parts of 

 Wharfedale and Ribblesdale. 



He would divide the rocks of the Carboniferous system into an 

 Upper Carboniferous or Anthraciferous Series, and a Lower Car- 

 boniferous or Calcareous Series ; and indicates the occurrence of 

 three very different faunas in the Carboniferous rocks, viz. : (i) a 

 Coal-measure fauna rich in fish-remains, with the moUuscan genera 

 Carhonicola, Anihracomya, and Nuiadites (essentially a fresh-water 

 fauna) ; (ii) the Lower Coal-measure and Grit fauna, largely 

 marine but littoral, with Aviculopecten, Posidonella, Nautilus, 

 Goniatites, and peculiar gasteropoda; and (iii) a Limestone fauna 

 essentially marine, very rich in brachiopods, and containing Fectea, 

 Avicula, Edmondia, Sanguinolites, and many other lamellibranchs, 

 gasteropods, such as Euomphalus, Pleurotomaria, MurcMsouia, and 

 Loxoneina, and certain peculiar cephalopods. 



2. " Notes on Volcanic Bombs in the Schalsteins of Nassau." By 

 Professor E. Kayser, Ph.D., For. Corr. G.S. (Communicated by the 

 Secretary.) 



The bombs forming the subject of this communication occur in 

 two localities in the neighbourhood of Oberscheld, near Dillenburg. 

 They are generally rounded, though sometimes angular, and vary 

 in size from that of a nut to that of a man's head. Each consists of 

 a kernel of coarse-grained rock representing a fragment of limestone 

 altered by metamorphism, surrounded by a rind of amygdaloidal 

 rock due to the inclusion of the fragments in molten lava. They 

 demonstrate the pyroclastic origin of the Schalsteins, and also prove 

 the similarity between the old Devonian volcanoes and those which 

 are now active. 



