186 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [Jan. 10, 



Dr. Sterry Hunt, read at the Bath meeting of the British Association, 

 *' On the Occurrence of Organic Kemains in the Lauren tian Rocks of 

 Canada." Besides, one of us, when in London last January, ex- 

 amining specimens of the '' remains " in question, and observing how 

 closely the rock containing them resembled the Ophite* of Conne- 

 mara, was led to suspect an identity of origin for both deposits. 

 Our interest in the matter was further excited on reading an 

 announcement in the ' Geological Magazine 'for last February, of the 

 discovery by Mr. W. A. Sandford, "■ verified " by Professor T. Rupert 

 Jones, of " Eozoonal structure in the Connemara marble" f. 



Considering that we resided near the locality which yielded the 

 latter rock, and that the determination whether, or not, it had resulted 

 from the growth of " Eozoon Canadense'^ would enable us to form a 

 positive opinion as to the age of the great metamorphic masses with 

 which it is interstratified, we felt ourselves called upon to undertake 

 an investigation promising so important a result J. 



"We commenced with no misgivings as to the " eozoonal " origin 

 of the Canadian Ophite, while our faith in the conclusion come 

 to by Sir Wilham Logan, and his able coadjutors, was strengthened 

 by subsequently reading the masterly papers which appeared in 

 No. 81 of the ' Quarterly Journal of the Geological Society.' Very 

 few having any knowledge of the construction of the calcareous 

 encasements of the various foraminifers, whether characterizing the 

 simple nubecularias or the complex nummulinas, could rise from 

 the perusal of those papers without feeling more or less disposed to 

 adopt the view that the Canadian Ophite had originated from the 

 superpositional, but otherwise indefinite, mode of growth of a gigantic 

 sessile spreading representative of the lowest known group of animals, 

 or without admitting that the view was based on sound reasoning 

 and deep thought. 



* The names ophite and serpentine have been indifferently employed by geo- 

 logists for the rock under description and some others allied to it ; but the first 

 one, which was used by Yitruvius, having priority, we have determined, after 

 some consideration, on employing it ; and as the second is generally applied by 

 mineralogists to the essential (silicated) mineral of Ophite, we shall restrict it to 

 this application in the present memoir. By adopting this plan much confusion 

 will be avoided, especially as many mineralogists and geologists are in the habit 

 of calling both the rock and its essential mineral by the name of serpentine. 

 Had it been necessary to call the rock serpentine, the name retinalite (as will be 

 seen hereafter) might have been retained for the mineral. 



t Op. cit. vol. ii. p. 88. 



J Sir Eoderick I. Murchison (Siluria, 2nd edit. p. 192) and Professor Harkness 

 (Geological Magazine, vol. ii. pp. 147, 148) are of opinion that the Connemara 

 metamorphic rocks are " Lower Silurian." From their discordance, both in 

 strike and dip, with the overlying Upper Silurian beds, their highly altered con- 

 dition, compared with the latter deposits (both of which circumstances favour 

 a greater chronogeological gap than is sanctioned by the opinion stated), and 

 their being devoid of Lower Silurian, Upper Cambrian, or other fossils, one of 

 us placed them, in an edition of his ' Synoptical Table of Aqueous E-ock -groups,' 

 in the " Lower Cambrian system — Sedgwick (? Huronian, Logan) "—thus, 

 " ? Cliffden (Connemara) Quartzites." This edition was printed in 1862, by 

 Mr. S. J. Mackie, F.G.S., editor of the ' Geologist,' and is entitled " Student's 

 Series, No. 21." 



