[Illustration: Fig. 6.--Cross Section of the Specimen represented in Fig. 8. The dark parts are the laminæ of calcareous matter converging to the outer surface.] About this time Dr. Hunt happened to mention to me, in connection with a paper on the mineralization of fossils which he was preparing, that he proposed to notice the mode of preservation of certain fossil woods and other things with which I was familiar, and that he would show me the paper in proof, in order that I might give him any suggestions that occurred to me. On reading it, I observed, among other things, that he alluded to the supposed Laurentian fossils, under the impression that the organic part was represented by the serpentine or loganite, and that the calcareous matter was the filling of the chambers. I took exception to this, stating that though in the slices I had examined no structure was apparent, still my impression was that the calcareous matter was the fossil, and the serpentine or loganite the filling. He said--"In that case, would it not be well to re-examine the specimens, and try to discover which view is correct?" He mentioned, at the same time, that Sir William had recently shown him some new and beautiful specimens collected by Mr. Lowe, one of the explorers on the staff of the Survey, from a third locality, at Grenville, on the Ottawa. It was supposed that these might throw further light on the subject; and accordingly Dr. Hunt suggested to Sir William to have additional slices of these new specimens made by Mr. Weston, of the Survey, whose skill as a preparer of these and other fossils has often done good service to science. A few days thereafter some slices were sent to me, and were at once put under the microscope. I was delighted to find in one of the first specimens examined a beautiful group of tubuli penetrating one of the calcite layers. Here was evidence, not only that the calcite layers represented the true skeleton of the fossil, but also of its affinities with the foraminifera, whose tubulated supplemental skeleton, as described and figured by Dr. Carpenter, and represented in specimens in my collection, presented by him, was apparently of the same type with that preserved in the canals of these ancient fossils. Fig. 7 is an accurate representation of the group of canals first detected by me. [Illustration: Fig. 7.--Group of Canals in the Supplemental Skeleton of Eozoon. Taken from the specimen in which they were first recognised. Magnified. (Camera tracing by Mr. H. S. Smith.)] On showing the structures discovered to Sir William Logan, he entered into the matter with enthusiasm, and had a great number of slices, as well as decalcified specimens, prepared, which were placed in my hands for examination.