Geological Society. 447 



educated geologist, making careful observations, and bringing a 

 well-trained and philosophic mind to grasp the details and com- 

 pare them with the experiences of others. Though not artistic, 

 his rough sketches of scenery are useful ; for he knows how to 

 indicate the real structure of the country. 



LIV. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 



[Continued from p. 134.] 



November 3, 1880.— Eobert Etheridge, Esq., F.K.S., President, 



in the Chair. 



rPHE following communications were read : — 

 -*- 1. " On the Serpentine and Associated Rocks of Anglesey, 

 with a Xote on the so-called Serpentine of Porthdinllevn (Caernarvon- 

 shire)." By Prof. T. G. Bonney, M.A., E.R.S., Sec. G.S. 



Several patches of serpentine are indicated on the Geological- 

 Survey map on the western side of Anglesey, near Tre-Yalley 

 station, and a considerable one on Holyhead island near Rhoscolyn. 

 These really include three very distinct varieties of rocks — (1) com- 

 pact green schistose rocks, (2) gabbro, (3) true serpentine. The 

 author described the mode of occurrence of each of these, and their 

 relations, the serpentine being almost certainly intrusive in the 

 schist, and the gabbro in the serpentine. The microscopic structure 

 of the various rocks was described in detail, especially of the last. 

 It presents the usual characteristics, and is an altered olivine rock 

 which has contained bronzite. One or two varieties are rather 

 peculiar ; an ophicalcite and a compact chloritic schist containing 

 chromite are also noticed. At Porthdinllevn there is no serpentine, 

 but an interesting series of agglomerates and (probably) lava-flows 

 of a "basic nature, which may now be denominated diabases. 



2. "Xote on the Occurrence of Remains of Recent Plants in 

 Brown Iron-ore." By J. Arthur Phillips, Esq., F.G.S. 



3. " Xotes on the Locality of some Fossils found in the Carboni- 

 ferous rocks at T'ang Shan, in the province of Chih Li, China." 

 By James W. Carrall, Esq., F.G.S. With a 2\ ote by AYm. Carruthers, 

 Esq., F.R.S., F.G.S. 



November 17, 1880. — Robert Etheridge, Esq., F.R.S., President, 

 in the Chair. 



The following communications were read : — 



1. " On Abnormal Geological Deposits in the Bristol District." 

 By Charles Moore, Esq., F.G.S. 



The author remarked that the Frome district shows numerous 

 unconformable Secondary deposits and " vein-fissures " resting upon 

 or passing down through the Carboniferous Limestone, as described 

 in his former paper (Quart. Journ. Geol. Soc. vol. xxiii. p. 449). 

 He gave some further particulars as to these deposits, and especially 

 described the occurrence of Postpliocene, Liassic, and Rhaetic 

 deposits in the Microlestes-quaiTy near Shepton-^Iallet. Here the 



