Further, the authors of the paper have no right to object to our regarding the laminated specimen as "typical" Eozoon. If the question were as to _typical ophite_ the case would be different; but the question actually is as to certain well-defined forms which we regard as fossils, and allege to have organic structure on the small scale, as well as lamination on the large scale. We profess to account for the acervuline forms by the irregular growth at the surface of the organisms, and by the breaking of them into fragments confusedly intermingled in great thicknesses of limestone, just as fragments of corals occur in Palæozoic limestones; but we are under no obligation to accept irregular or disintegrated specimens as typical; and when objectors reason from these fragments, we have a right to point to the more perfect examples. It would be easy to explain the loose cells of _Tetradium_ which characterize the bird's-eye limestone of the Lower Silurian of America, as crystalline structures; but a comparison with the unbroken masses of the same coral, shows their true nature. I have for some time made the minute structure of Palæozoic limestones a special study, and have described some of them from the Silurian formations of Canada.[AS] I possess now many additional examples, showing fragments of various kinds of fossils preserved in these limestones, and recognisable only by the infiltration of their pores with different silicious minerals. It can also be shown that in many cases the crystallization of the carbonate of lime, both of the fossils themselves and of their matrix, has not interfered with the perfection of the most minute of these structures. [Footnote AS: In the _Canadian Naturalist_.]