All this seems sufficiently reasonable, more especially since no mineralogist has yet succeeded in giving a feasible inorganic explanation of the combination of canals, laminæ, tubulation and varied mineral character existing in Eozoon. But then comes the strange fact of its apparent isolation without companions in highly crystalline rocks, and with apparently no immediate successors. This has staggered many, and it certainly, if taken thus baldly, seems in some degree improbable. Recent discoveries, however, are removing this reproach from Eozoon. The Laurentian rocks have yielded other varieties, or perhaps species of the genus, those which I have described as variety Acervulina, and variety Minor, and still another form, more like a Stromatopora, which I have provisionally named _E. latior_, from the breadth and uniformity of its plates.[56] There are also in the Laurentian limestone cylindrical bodies apparently originally tubular, and with the sides showing radiating markings in the manner of corals, or of the curious Cambrian Archæocyathus. Matthew, a most careful observer, has found in the Laurentian limestone of New Brunswick certain laminated bodies of cylindrical form, constituting great reefs in the limestone, and in the slates linear flat objects resembling Algæ or Graptolites, and spicular structures resembling those of sponges.[57] Britton has also described from the Laurentian limestone of New Jersey certain ribbon-like objects of graphite which he regards as vegetable, and names _Archæophyton Newberryii_.[58] Should these objects prove to be organic, Eozoon will no longer be alone. Besides this the peculiar bodies named Cryptozoum by Hall, and which are intermediate in structure between Eozoon and Loftusia, have now been found as low as the Lower Cambrian.[59] Barrois has also recently announced the discovery of forms which he regards as akin to the modern Radiolaria, creatures of a little higher grade than the Foraminifera, in the "Archæan" rocks of Brittany.[60] Thus Eozoon is no longer isolated, but has companions of the same great age with itself. The progress of discovery is also daily carrying the life of the Cambrian to lower beds, and thus nearer to the Laurentian. It is not unlikely that in a few years a pre-Cambrian fauna will force itself on the attention of the most sceptical geologists. [56] Notes on Specimens of Eozoon, "Memoirs of Peter Redpath Museum," 1888. [57] _Bul. Nat. Hist. New Brunswick, No. IX._, 1890. [58] _Annals N. Y. Academy of Science_, 1888. [59] Walcott, Lower Cambrian, 1892. [60] _Natural Science_, Oct., 1892. References:--"Life's Dawn on Earth," London, 1875. (Now out of print.) "Specimens of Eozoon Canadense in the Peter Red path Museum, Montreal," 1888. (This memoir contains reference to previous papers.) Appended Notes.