TEANSACTIONS OF SECTION C. 679 



6. On Bucklandium diluvii, Ki'mig, a Siluroid Fish from the London Clay 

 of Shejypey. By A. Smith Woodward, F.G.S., F.Z.S. 



In his well-known 'Icones Fossilium Sectiles,' pi. viii., No. 91, Kouig fipfure.s a 

 remarkable fossil irom the London clay of Sheppey, which is mentioned in the text 

 as not certainly determinable, but generally regarded, by the anatomists who have 

 examined it, as pertaining to some type of lizard. This specimen is preserved in 

 the British Museum, and the author has deteruiined that it is truly the imperfect 

 head and pectoral arch of a Siluroid. The roof of the skull is preserAed almost as 

 far forwards as the middle of the frontals ; the pectoral arch is in position, though 

 .slightly bent backwards ; and the mass of anchylosed anterior vertebras, with the 

 basioccipital, is displaced downwards and thrown beneath the clavicles. All the 

 bones are remarkably strong, and the exposed surfaces are ornamented with large 

 tubercles. The head must have been originally somewhat deeper than broad, and 

 the roof exhibits no flattening, but is strongly arched from side to side. Posteriorly, 

 the supraoccipital projects in the usual manner, probably to meet a dermal plate 

 upon the nape ; and the post-temporal element seems to be merged with the bones 

 of the postero-lateral angles of the cranium. It is impossible to determine the 

 family-position of the genus in the usual manner, but the skulls of the West 

 African Auchenoglanis and Synodontis appear to approach the fossil most closely. 

 The provisional name of Bucklandium diluvii may be retained ; and the hsh is 

 interesting as being the earliest undoubted Siluroid hitherto discovered. 



7. On the Origin of Graphite in the Archaean Roclcs, with a Review of the 

 alleged Evidence of Life on the Earth in Archcean Time. By the Rev. 

 A. Irving, B.Sc, B.A., F.G.S. 



Attention is drawn to the occurrence of carbon in meteorites and its supposed 

 evidence of the pre-existence of vegetation, reference being made to the recent 

 experiments of Mr. Lockyer. Mobius, Etheridge, Dr. Sterry Hunt, Dr. Dawson, 

 and Dr. Geikie are referred to as having adopted a similar argument or else admitted 

 the presence of graphite to be evidence in that direction. References are made to 

 the writings of Oredner and Von Hauer as to its actual occurrence in the archsean 

 gneisses and schists. The general assumption of the phytoyetiic oriyin of graphite 

 which has hitherto prevailed is found to derive no support from the specimens 

 preserved in the national collection at South Kensington, since their structures can 

 all be explained on mechanical principles. The only direct evidence of phytogenic 

 origin is its occurrence in later rocks as an extreme carbonisation-product, but this 

 clearly is no proof of such an origin for the archsean. 



Other ways are then con.sidered in which elementary graphitic carbon is 

 produced without the intervention of organic life, such as 



(1) In the case of pig-iron. 



(2) The reduction of CO,, by the alkali-metals and by magnesium, and the 

 reduction of hydrocarbons by chlorine. 



(3) The dissociation of hydrocarbons by the spark-stream and by the contact- 

 action of heated solid surfaces. 



The last-mentioued process is conclusively demonstrated by the experimental 

 results obtained during the last three months in the author's laboratory, carbon 

 being cojiiousl}' deposited from the hydrocarbons of common coal-gas by the simple 

 contact-action of red-heated fragments of pumice (cf. the author's paper ' On Con- 

 tact-action ' read before Section B). 



The known conditions under which acetylene, marsh-gas, and some more 

 complex hydrocarbons can be formed synthetically were referred to, as well as the 

 spectroscopic evidence of the existence of hydrocarbons in the heads of some 

 comets. Such conditions probably obtained when the minerals of the archsean 

 gneisses were formed by primary paramorphism from a state of dry fusion. It is 

 therefore maintained that the necessarily phytogenic origin of archaean graphite is 

 a pure assumption, and can no longer be urged in proof of archsean organic life. 



