TUDOR SPECIMEN OF EOZOON. 353 



formed alonp: the linos of cleavage. In one case a thin vein extends 

 across the whole thickness of the slab along a line that was possibly 

 a true crack. In one or two places the solvent acted along a kind 

 of minute pipe, so that the calcite appears as a circular patch 

 entirely surrounded by the calc-mica-schist. Some of the bands 

 have the whole thickness formed of one crystal, but in other cases 

 they are occupied by a mosaic, the separate constituents of which 

 have the characteristic irregular polygonal outlines. 



There is a further convincing proof of the later origin of the 

 crystalline calcite where projections of the calc-mica-schist extend 

 into the calcite ; this has been deposited in such intimate connexion 

 with these patches that a certain amount of crystalline continuity 

 has been established, and the cleavage-planes pass uninterruptedly 

 from the one to the other (fig. 3). Further, the regular distribution 

 of the graphite seems to show that the transparent calcite was 

 formed by the solution and recrystallization of the schist, as the 

 inclusions appear to have been primary impurities rather than to 

 have originated as infiltrations. 



In conclusion, it should be pointed out that no opinion is here 

 exi)ressed as to the nature and origin of the other types of Eozoon. 

 It is only maintained that as the Tudor specimen lacks all the 

 structures (except the mere alternation of irregular layers of diH'erent 

 composition) which caused the typical Eozoon to be regarded as 

 organic, the argument based upon it to the effect that all these 

 structures have been preserved in calcite alone is not sustained by 

 a further examination of the specimen. But if it still be contended 

 that Sir J. W. Dawson has rightly identified this Tudor specimen, 

 then Eozoon is not organic, as in this case it is dne to secondary 

 alterations produced long after the consolidation of the limestone, 

 and eveu after the metamorphic action which converted it into a 

 caJc-mica-schist. 



(e) Stratigrapliical Position of the '' Hastings series.'' — In regard 

 to the stratigraphical position of the specimen it should be remarked 

 that the Hastings series, including the Tudor limestone, cannot now 

 be regarded as Lower Laurentian, to which horizon it was assigned 

 by Sir Wm. Logan in 1867 *. The detailed mapping of Mr. H. G. 

 Vennor f has conclusively disproved this opinion and established 

 the correlation of these beds with the Grenville series, and thus 

 led to the abandonment of the term " Hastings series " as applied 

 to a separate group +. It is quite possible, as Dr. Lawson § has 



* ' On new Specimens of Eozoon,' Quart. Journ. Geol. Soo. vol. xxiii. (18G7) 

 p. 254. 



t ' Report of Mr. H. G. Vennor on Hastinfrs County,' Rep. Progress Geol. 

 Surv. Canada, 18()6-()9 (Montreal, 1870), pp. 1-43-171 ; H. G. Vennor, 'Reports 

 of Surveys in the counties of Renfrew, Pontiac, and Ottawa, &c.,' op. cit. 1876- 

 77 (1878). pp. ii44-32(). 



X Op. cit: 1876-77, p. 256. 



§ A. C. Lawson, ' The Arc]ia[^an Geology of the Region IS^ortli-west of Lake 

 Superior,' p. 86 of the 'Etudes sur les Schistee cristallins,' of which separate 

 co))ies were issued at the London Session of the Congres geologique inter- 

 national, but have not yet been published. 



