Page:Quarterly Journal of the Geological Society of London, vol. 33.djvu/99

Rh AUSTRALIAN CAINOZOIC ('TERTIARY) DEPOSITS. 69 rhynchus, and Eupatagus gives a Nummulitic-of-Europe-and-India fades to the fauna, whilst the Cretaceous aspect is presented by G atopy gus, Holaster, Micraster, and the Rhynchopygus with the Ananchytic-looking apex. . It is evident that this Cainozoic fauna contains the elements of two previous ones, and that it foreshadowed a part of the recent Australian, whilst some of its species, with some modifications, re- semble those of the neighbouring- seas. The general facies of the whole is older than is warranted by the geological position. Nearly all the genera are peculiar from their great vertical or horizontal range, the exceptions being in the cases of Arachnoides and Maretia. Two of the three species which are common to the Cainozoic and Eecent faunas have a wide distribution in the Pacific, and one also in the Atlantic. Four of the species which resemble recent Australian forms to a certain extent are very characteristic. They are Leiocidaris austrcdice, Arachnoides Loveni, Eupatagus Laiibei, and Lovenia (Hemipatagus) Forbesi. They give the so-called Miocene facies, which, however, is suffi- ciently indefinite. This appearance is added to by the other species belonging to genera still existing in the neighbouring seas, the scattering of forms having been from South Australia to the east and especially to the north. Of 25 genera belonging to the recent Australian fauna only 7 are represented in the Australian Cainozoic deposits — namely, Arach- noides, Echinobrissas, Eupatagus, Lovenia, ScJiizaster, Echinanthus, and Echinarachnius. The most truly Australioid genera, and those which give the facies to the recent fauna, are not found in the deposits; for no species have been discovered of Strongylocentrotus, Microcyphus, Salmans, Amblypneustes, and Holopneustes. These Echinoidea were not then on the area ; and their place was occupied by numerous Spatangoids, most of which foreshadowed those of the Eecent fauna ; and these, from their range, are not very character- istic of it. The spines which were found, but not associated with their tests, resemble those of some recent Australian genera, such as Phyllacan- thus, Goniocidaris, Stephanocidaris and Brissus: the nature of the spines of Leiocidaris australice from the Cainozoic is unknown. It is not safe to argue from such resemblances concerning specific or even generic relationships ; but nevertheless the presence of the spines should be an incentive to the further search for Cidaridee. It is interesting to find the fossil Echini affording the same evidences as the fossil corals respecting the affinities of the Cainozoic and recent Australian faunas. Of the 31 species of corals not one has yet been found in the recent coral fauna ; and out of 20 recent Australian coral genera, only three very worldwide ones are repre- sented in the Cainozoic deposits. It was remarked in the essay on the fossil corals that they ap- peared to have a facies of the fauna of the seas to the north of extratropical Australia ; and this holds good for the Echini. The inference that there was then a warmer climate in the southern