[The following note was added in a reprint of the paper in the Canadian Naturalist, April, 1865.]
“Since the above was written, thick slices of Eozoon from Grenville have been prepared, and submitted to the action of hydrochloric acid until the carbonate of lime was removed. The serpentine then remains as a cast of the interior of the chambers, showing the form of their original sarcode-contents. The minute tubuli are found also to have been filled with a substance insoluble in the acid, so that casts of these also remain in great perfection, and allow their general distribution to be much better seen than in the transparent slices previously prepared. These interesting preparations establish the following additional structural points:—
“1. That the whole mass of sarcode throughout the organism was continuous; the apparently detached secondary chambers being, as I had previously suspected, connected with the larger chambers by canals filled with sarcode.
“2. That some of the irregular portions without lamination are not fragmentary, but due to the acervuline growth of the animal; and that this irregularity has been produced in part by the formation of projecting patches of supplementary skeleton, penetrated by beautiful systems of tubuli. These groups of tubuli are in some places very regular, and have in their axes cylinders of compact calcareous matter. Some parts of the specimens present arrangements of this kind as symmetrical as in any modern Foraminiferal shell.
“3. That all except the very thinnest portions of the walls of the chambers present traces, more or less distinct, of a tubular structure.
“4. These facts place in more strong contrast the structure of the regularly laminated species from Burgess, which do not show tubuli, and that of the Grenville specimens, less regularly laminated and tubulous throughout. I hesitated however to regard these two as distinct species, in consequence of the intermediate characters presented by specimens from the Calumet, which are regularly laminated like those of Burgess, and tubulous like those of Grenville. It is possible that in the Burgess specimens, tubuli, originally present, have been obliterated, and in organisms of this grade, more or less altered by the processes of fossilisation, large series of specimens should be compared before attempting to establish specific distinctions.”
(B.) Original Description of the Specimens added by Dr. Carpenter to the above—in a Letter to Sir W. E. Logan.
[Journal of Geological Society, February, 1865.]
"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.’