511 



in his Paper " On New Specimens of Eozoon,"* published at the same 

 time as Dr. Dawson's. 



We shall now proceed to examine the specimen from Tudor. 



In the first place, the " fossil," which has the general appearance 

 of a Penestella (not that we have the least suspicion of its having any 

 relation to the latter, or any other organism whatever), is exceedingly 

 thin, and consists of a number of parallel or sub-parallel slender string- 

 like ribs, strangely called " septa," lying in one plane ; which ribs 

 "divide and reunite at short distances :" a " few transverse plates, or 

 connecting columns, are visible;" otherwise the so-called septa "do 

 not coalesce," except on one of its sides. Taking Dr. Dawson's view, 

 the specimen is to be regarded as a detached " weathered section" that 

 has got " broken" from an individual " Eozoon" perpendicularly to its 

 " septa" before it became imbedded. Considering the arrangement and 

 thinness of the ribs — "scarcely two lines in thickness" — and the compa- 

 ratively large size of the specimen, " six and a half inches in length, 

 and about four inches broad," there seems much improbability that it 

 could have got detached from a massive " organism," such as " Eozoon" 

 is supposed to have been. 



Secondly, the " septa are in the state of white carbonate of lime," 

 some "portions" of which exhibit " cleavage planes." "There are 

 also a number of small veins or cracks passing nearly at right angles to 

 the septa, and filled with carbonate of lime, similar in general appear- 

 ance to the septa themselves;" and ihe same mineral, in larger examples, 

 occurs in other places, a "white patch" of it having " obliterated the 

 chambers" in one part. 



From these statements, and the presence of nothing more than 

 a " doubtful microscopic structure" in some parts of the "fossil," and 

 from the appearances presented by the "admirable photograph" of it, 

 " executed by Mr.Norman,"f we feel ourselves warranted in suggesting 

 that the " septa,'' " veins," and " white patches," are all of one and the 

 same origin — purely mineral. 



Thirdly, the "matrix" of the "fossil" is a "dark-coloured, coarse, 

 laminated limestone, holding sand, scales of mica, and minute grains and 

 fibres of carbonaceous matter." The ' ' septa," it is stated, " present, for 

 the most part, merely traces of structure, consisting of small parts of 

 canals, filled with the dark colouring matter of the limestone."]: A 

 representation of a " section of one" of the septa is given by Dr. 



* "Quarterly Journal of Geological Society," No. 91, August, 1887, pp. 253-257- 

 f The lithograph of the specimen illustrating Dr. Dawson's paper represents the 

 " septa," &c, less imperfectly denned than they are in the photograph ; for copies of 

 which we are indebted to Dr. Carpenter. 



% Dr. Sterry Hunt, the Chemist and Mineralogist of the Canadian Geological Survey, 

 states that the fossil is " penetrated by the blackish argillaceous limestone which en- 

 velopes it." — " Esquisse Geologique du Canada," p. 7. 



E. I. A. PROC. VOL. X. 3 T 



