"The careful examination which I have made, in accordance with the request you were good enough to convey to me from Dr. Dawson and to second on your own part, with the structure of the very extraordinary fossil which you have brought from the Laurentian rocks of Canada,[Q] enables me most unhesitatingly to confirm the sagacious determination of Dr. Dawson as to its Rhizopod characters and Foraminiferal affinities, and at the same time furnishes new evidence of no small value in support of that determination. In this examination I have had the advantage of a series of sections of the fossil much superior to those submitted to Dr. Dawson; and also of a large series of decalcified specimens, of which Dr. Dawson had only the opportunity of seeing a few examples after his memoir had been written. These last are peculiarly instructive; since in consequence of the complete infiltration of the chambers and canals, originally occupied by the sarcode-body of the animal, by mineral matter insoluble in dilute nitric acid, the removal of the calcareous shell brings into view, not only the internal casts of the chambers, but also casts of the interior of the 'canal system' of the 'intermediate' or 'supplemental skeleton,' and even casts of the interior of the very fine parallel tubuli which traverse the proper walls of the chambers. And, as I have remarked elsewhere,[R] 'such casts place before us far more exact representations of the configuration of the animal body, and of the connections of its different parts, than we could obtain even from living specimens by dissolving away their shells with acid; its several portions being disposed to heap themselves together in a mass when they lose the support of the calcareous skeleton.' [Footnote Q: The specimens submitted to Dr. Carpenter were taken from a block of Eozoon rock, obtained in the Petite Nation seigniory, too late to afford Dr. Dawson an opportunity of examination. They are from the same horizon as the Grenville specimens.--W. E. L.] [Footnote R: _Introduction to the Study of the Foraminifera_, p. 10.] "The additional opportunities I have thus enjoyed will be found, I believe, to account satisfactorily for the differences to be observed between Dr. Dawson's account of the Eozoon and my own. Had I been obliged to form my conclusions respecting its structure only from the specimens submitted to Dr. Dawson, I should very probably have seen no reason for any but the most complete accordance with his description: while if Dr. Dawson had enjoyed the advantage of examining the entire series of preparations which have come under my own observation, I feel confident that he would have anticipated the corrections and additions which I now offer.