Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/101

Rh AUSTRALIAN CAIXOZOIC (TERTIARY) DEPOSITS. 71 13. The same, apical system, enlarged. 14. Eupatagus rotundus, sp. n., side view of test, natural size. 15. The same, apical system and fascicle, natural size. 16. The same, actinal surface, showing peristome and floscelle, natural size, a, a tubercle, enlarged. 17. The same, periproct and subanal fasciole, natural size. 18. Eupatagus Laubei, sp. n., apical system and fascioles, twice natural size. Plate IT. Fig. 1. Maretia anomala, sp. n., abactinal surface, natural size. 2. The same, actinal surface. 3. Boss of a tubercle of the same, from above, enlarged. 4. The same, side view. 5. Lovenia Forbesi, Woods and Duncan, from above, natural size. 6. The same, periproct and subanal fasciole, twice natural size. 7. Plastron of the same, three times natural size. 8. Abactinal surface of the same, about four times natural size. Discussion. Mr. Evans was glad to find that this subject, concerning which ho had lately expressed his own views, had been taken up by the author ; but he thought it possible that Dr. Duncan would, on further consideration, be inclined to modify somewhat the theory promulgated in this paper in favour of some other view. In order to account for the occurrence of reef-building corals of Miocene age in latitudes now too cold for them, the author had reverted to the old idea of the vertical position of the poles. If the interior of the earth is fluid, a sliding crust, such as the speaker had formerly suggested, is possible, though it would be difficult to prove the ex- istence of a fluid interior, and still more difficult, did that exist, to prove that the crust would slide en it. But even supposing the earth to be a nearly solid body, elevations and depressions enough must take place on the surface to alter the relative positions of the poles with regard to the surface of the earth. Because there were proofs of warmer climate having existed in Miocene times in Greenland, near the one pole, and in Xew Zealand near the other, there was no need to suppose that belts of warmer temperature had extended nearer the poles than at present ; for the same sliding of the crust that brought Greenland nearer the equator would also bring Xew Zealand nearer the tropics, both being on nearly the same meridian, but on opposite sides of the globe. The subject was one that deserved the attention of geologists, as it lay at the root of many important questions affecting the past history of the earth. Professor Hughes believed implicitly what the astronomers told him must be ; and if observations on the distribution of life neces- sitated any thing more than such alterations of climate as could be accounted for by geographical changes and modification and adapta- bility in the forms of life, he would prefer to leave it as one of the many things he could not explain, than accept an explanation in- consistent with accepted astronomical theories. If, as explained by Sir John Herschel, the transference of large masses from one part