406 PKOCEEDINGS OF THE GEOLOGICAL SOCIETY. [June 23, 



should be remembered that the surfaces of basaltic rocks are very 

 susceptible of decay. 



Discussion. 



Mr. Etheridge remarked on the similarity of the Oolitic speci- 

 mens to those from the Cotteswold Hills, and also to those from 

 the Holy Land. Similar fossils also occurred in the far east, and 

 even in Australia. 



The Peesident remarked that this range was not greater than 

 that of some recent species ; and in answer to his inquiry, 



Mr. Blaneoed stated that there were no marks of glaciation dis- 

 cernible in Abyssinia, the excavation of the valleys being appa- 

 rently due to the excessive rainfull. 



5. On the Geaphite of the Laueentiat^^ of Canada. 

 % Prof. J. W. Dawson, LL.D., P.R.S., E.G.S. 



(The publication of this paper is postponed.) 

 [Abstract.] 



The author described the modes of occurrence of great quantities 

 of graphite in the Laurentian limestones of Canada. It occurs both 

 in beds and veins, the latter generally not true fissures, but shrinkage- 

 cracks or segregation -veins. It is also disseminated, in scales &c., 

 through the substance of the rocks. The graphitiferous rocks are 

 widely spread, both in Canada and the neighbouring portion of the 

 United States. The author discusses the origin of this graphite, 

 which he ascribes to the conversion of the remains of plants into 

 bituminous matter, from which the graphite has in its turn been 

 derived. In some cases he has found traces of fibres which he 

 thought might be the remains of terrestrial plants. In conclusion 

 the author referred to the interest attaching to this matter in con- 

 nexion with the study of the conditions prevailing at the time of the 

 deposition of these hmestones, and especially as furnishing evidence 

 of an abundance of vegetable life in the *' Eozoic " period. 



DiscirssioN. 



Prof. Beatlet inquired whether there was any proof that the sub- 

 stance called graphite might not be anthracite. He did not himself 

 know of any instance of the passage of one of those substances into 

 the other, and regarded graphite as of chemical origin, and not as 

 directly derived from vegetable matter. 



Mr. Mallet did not think that it was possible for any organic 

 forms to remain in a substance so purely crystalhne as typical 

 graphite. The presence of organic remains was an argument in 

 favour of the masses mentioned in the paper being lustrous anthra- 

 cite rather than graphite. 



