X INTRODUCTION. 



composition. If the specimens had been obtained from the 

 altered rocks of the Lower Silurian series, there would have 

 been little hesitation in pronouncing them to be fossils." 



1864. American Journal of Science, March 1864, p. 273. 



Sir W. E. Logan announced that Dr. Dawson had discovered 

 in the Canadian ophite structures which it was decidedly his 

 belief were organic and foraminiferal. 



1864. On the Occurrence of Organic Remains in the Laurentian 

 Rocks of Canada. By Sir W. E. Logan, F.R.S., F.G.S.; 

 with Communications by J. W. Dawson, LL.D, F.R.S., 

 on the Structure, and by T. Sterry Hunt, F.R.S., on 

 the Mineralogy of the same remains. 



Paper read at the Bath Meeting of the British Association, 

 September 1864. 



1864. On the Structure of certain Organic Remains in the Laurentian 

 Limestones of Canada. Dr. J. W. Dawson. Q. J. G. S. 

 vol. xxi. pp. 51-59. 



1864. Additional Note on the Structure and Affinities of Eozoon 



Canadense. Dr. W. B. Carpenter. Op. cit. pp. 59-66. 

 Both writers assume that the calcareous or dolomi tic layers of the 

 specimens brought under notice by Logan constitute the skeletal 

 portion of "Eozoon Canadense" and that the siliceous layers, 

 whether serpentine, white pyroxene, or loganite, are casts of its 

 cells or chambers. Dawson, having detected branching configura- 

 tions and rods or plates in the " skeleton," and taking them for 

 casts of canals and stolons, identified them with the canal system 

 and stolons of a foraminiferal organism ; and Carpenter, observing 

 a fibrous lamina often surrounding the " chambers," pronounced 

 its fibres to be casts of tubuli such as characterize the proper wall 

 of a nummuline foraminifer. The serpentine layers frequently 

 present themselves more or less excavated and divided ; but often 

 they are broken up into short plates and detached spheroids irre- 

 gularly lobulated. The presumed organism in the former case is 



