4oo NATURAL SCIENCE. j UNE , 



below, and the thicker and more regular laminae above or without. I 

 need scarcely say that this would be in direct opposition to the 

 descriptions of Dr. Carpenter and myself, based on the study of a 

 great number of specimens in situ. I observe, however, that Zittel 

 (Palaeontologie, fig. 47) places Eozobn in this inverted position, which 

 may have led to the error in question. 



It is proper perhaps to repeat in this connection that, in certain 

 layers of the Grenville limestone, grains and concretions of serpentine 

 and malacolite occur without Eozobn, and specimens of Eozobn with 

 only so much of such minerals as may be contained in their chambers. 

 There are also instances in which specimens of Eozobn occur attached 

 to or partially imbedded in such nodules, just as sponges and other 

 organisms occur associated with flints in chalk, or as stromatopores 

 occur in connection with concretions of chert in Palaeozoic limestones. 

 As to the origin of the concretions themselves, from whatever source 

 their materials may have been originally derived, their isolation in the 

 limestone and the manner in which they occur in connection with 

 surfaces of deposition, render it certain that their introduction as well 

 as that of the individuals of Eozobn was contemporaneous with the 

 formation of the limestone. 



Quite recently Kemp and Smyth, two able U.S. geologists, have 

 published {Bull. Geol. Soc. Amev., March, 1895), Observations on the 

 Laurentian Limestones of the Adirondack Region of New York, in 

 which they fully recognise their extended and sedimentary character, 

 though in that mountainous region they are even more altered and 

 disturbed, and also more invaded by igneous masses than in the 

 Canadian area. They do not seem to have met with any " contact- 

 banding " comparable to Eozobn, though from microscopic examina- 

 tion I know that detached fragments of Eozobn exist in some of the 

 limestones of the Adirondack region. 



The above plain statements of facts are, I think, sufficient to 

 show that the specimens of Eozobn found in the Laurentian limestones 

 of Canada in no respect resemble in their associations and mode of 

 occurrence the banded forms from Mt. Somna described in the paper 

 in question. Additional details may be found in my Memoir on the 

 " Specimens of Eozoon in the Peter Redpath Museum," and in other 

 publications referred to in that work. 3 



2. Form and Structure. — In so far as can be judged from the 

 plates, some of the forms described in the paper lie in bands parallel 

 to igneous veins, like the laminated borders or selvages common in 

 every part of the world, and of which we have good instances in the 

 trappean dykes of the Montreal mountain ; or they appear as rounded 

 masses in the manner of nodules or geodes. Thus, in so far as mere 

 lamination or banding is concerned, they have a certain resemblance 

 to Eozobn ; but, on closer inspection, essential differences may be 



H Montreal, 1888, pp. 106. See also " Salient Points in the Science of the 

 Earth" by the same author, 1893. 



