Rejjorts and Proceedings — Geological Society. 141 



plants by Dr. A. Schenk, and twenty-five plates are devoted to illus- 

 trating the various forms. A study of this fossil flora from many 

 different localities conclusively shows that the Coal-beds of China 

 belong to two different periods, Carboniferous and Jurassic. From 

 the earlier or true Carboniferous about forty species from twelve 

 different localities are recorded, and it appears that the most important 

 and extensive of the known Coal-fields belong to this horizon. From 

 seven other localities nearly thirty species of Equisetacas, Ferns, 

 Cycads, and Conifers are enumerated, and the identity or close affinity 

 of most of these species with those met with in the Lower and 

 middle Jurassic strata of England, Germany, Eussia, Siberia, and 

 Spitzbergen.. conclusively shows their relative age. G. J. H. 



:Ee,:E:F'Os,TS .A.3rjD :F'I^ooJa:EIDIIf^c3-s. 



Geological Society of LojStdon. 



1.— January 23, 1884.— R. Etheridge, Esq., F.R.S., Vice-President, 

 in the Chair. — The following communications were read : — 



1. " On the Serpentine and associated Eocks of Porthalla Cove." 

 By J. H. Collins, Esq., F.G.S. 



In a paper read before the Eoyal Geological Society of Cornwall 

 in November, 1879, the author described the rocks at Porthalla Cove 

 as consisting of much-contorted strata of slaty green and red ser- 

 pentine and hornblende-rocks, which he regarded as "highly altered 

 Lower Silurian stratified rocks." Prof Bonney has since (Q. J. 

 G. S. vol. xxxix. p. 1) described the same rocks, and explained 

 the structure of the district quite differently, correlating the rocks 

 with those of his " Archgean metamorphic series " at the Lizard. 

 The author in the present paper argued in support of his previously 

 expressed opinion. 



He stated that within a space of little more than 100 yards the 

 following varieties of rocks may be distinguished : — 1. Crumpled 

 shales and slates, sometimes containing veins and layers of quartz 

 and flakes of mica ; passing into 2, greenish slates of talcose appear- 

 ance ; passing into 3, soft and shaly mudstone ; passing into 4, red 

 and green bands of serpentine; often passing into 5, hornblende- 

 schists of the type characterizing the locality ; and 6, pinkish or 

 greyish granulite. No. 1 he regarded as belonging to a younger 

 series than the rest ; Nos. 2 and 6 are the rocks supposed to repre- 

 sent Prof. Bonney's micaceous group of the Archaean series ; and 

 No. 4 was regarded by the latter as intrusive. 



The author stated that the slates, shales, serpentine, and horn- 

 blende-schist appeared to him to be distinctly interstratified, and 

 the granulite to be distinctly intrusive. At Nelly's Cove, about 

 half a mile north of Porthalla, there are a few thin bands of black 

 limestone, like those of Gerrard's Bay, and also containing frag- 

 ments of Crinoids ; these were regarded by the author as of Lower 

 Silurian age, and as underlying the Porthalla rocks considered by 

 Prof. Bonney to represent the Archaean metamorphic series of the 

 Lizard Head. The author discussed at considerable length the 



