Geological Society. 215 



Natural History. After his settling in Australia lie followed his 

 bent in Geology, and got an insight into the general structure of 

 the eastern mountain-ranges and of the strata flanking them on the 

 east ; and he was one of the first to recognize the gold-drifts and 

 auriferous rocks. The relative position and age of the Coal- 

 measures there he also studied ; and he philosophically concluded 

 that certain plant-remains in the Australian coal did not neces- 

 sarily give it a Jurassic age, or remove it from the Paleozoic series, 

 because they resembled, or even were identical with, a fossil plant 

 found in the Oolites of Yorkshire. The persistence of many low 

 organisms, the wide extent and long-continued emigration of suc- 

 cessions of similar creatures, as well as other considerations, strongly 

 supported the veteran observer in his discussions with those who 

 would draw equally definite demarcations for the extinct faunas and 

 floras of Britain and for those of its antipodes. Of this and many 

 other subjects, interesting to both the historian and the student of 

 geology, this last edition of Mr. Clarke's condensed observations 

 contains a complete account, involving, too, a considerable series of 

 notes on the geological structure and history of other regions. It 

 was finished on June 2, 1878, the eightieth birthday of the enthu- 

 siastic author, who had for many years given his best exertions to 

 the elucidation of Australian geology, to its beneficial application 

 to his fellow countrymen, and to the dissemination of a sound 

 knowledge of his favourite science to all whom his words and 

 writings could reach. He ceased from his labours before the year 

 was out, respected and honoured, leaving behind him the legacy of 

 good work, with its sure results in advancing the welfare of his 

 fellow men. 



XXXVI. Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 

 [Continued from p. 143.] 



Jan. 22, 1879.— Henry Clifton Sorby, Esq., F.R.S., President, in 



the Chair. 

 rPHE following communications were read : — 

 -*- 1. " On Community of Structure in Rocks of Dissimilar Origin." 

 By Frank Rutley, Esq., F.G.S. 



After alluding to the community in mineral constitution of certain 

 rocks to which different names have been applied, and indicating 

 the advisability of retaining some old terms in a provisional 

 sense, questions relating to the causes of the angular and rounded 

 characters of certain rock-constituents were discussed. The 

 author then described some of the more common structural 

 peculiarities met with in rocks of various origin, especial at- 

 tention being directed to those in which microcrystalline, cryp- 

 tocrystalline, or microfelsitic conditions have been either nor- 

 mally developed or superinduced; while other rocks were de- 



