These fossils, however, show no very distinct canal system or supplemental skeleton, but this also appears in those forms which have been called Caunopora or Cœnostroma. In these the plates are traversed by tubes, or groups of tubes, which in each successive floor give out radiating and branching canals exactly like those of Eozoon, though more regularly arranged; and if we had specimens with the canals infiltrated with glauconite or serpentine, the resemblance would be perfect. When, as in figs. 44 and 45 A, these canals are seen on the abraded surface, they appear as little grooves arranged in stars, which resemble the radiating plates of corals, but this resemblance is altogether superficial, and I have no doubt that they are really foraminiferal organisms. This will appear more distinctly from the sections in fig. 45 B, C, which represents an undescribed species recently found by Mr. Weston, in the Upper Silurian limestone of Ontario. [Illustration: Fig. 44. _Caunopora planulata, Hall--Devonian; showing the radiating canals on a weathered surface._ (_After Hall._)] [Illustration: Fig. 45. _Cœnostroma--Guelph Limestone, Upper Silurian, from a specimen collected by Mr. Weston, showing the canals._ (_a._) Surface with canals, natural size. (_b._) Vertical section, natural size. (_c._) The same magnified, showing canals and laminæ.] There are probably many species of these curious fossils, but their discrimination is difficult, and their nomenclature confused, so that it would not be profitable to engage the attention of the reader with it except in a note. Their state of preservation, however, is so highly illustrative of that of Eozoon that a word as to this will not be out of place. They are sometimes preserved merely by infiltration with calcite or dolomite, and in this case it is most difficult to make out their minute structures. Often they appear merely as concentrically laminated masses which, but for their mode of occurrence, might be regarded as mere concretions. In other cases the cell-walls and pillars are perfectly silicified, and then they form beautiful microscopic objects, especially when decalcified with an acid. In still other cases, they are preserved like Eozoon, the walls being calcareous and the chambers filled with silica. In this state when weathered or decalcified they are remarkably like Eozoon, but I have not met with any having their minute pores and tubes so well preserved as in some of the Laurentian fossils. In many of them, however, the growth and overlapping of the successive amœba-like coats of sarcode can be beautifully seen, exactly as on the surface of a decalcified piece of Eozoon. Those in my collection which most nearly resemble the Laurentian specimens are from the older part of the Lower Silurian series; but unfortunately their minute structures are not well preserved.