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I .—INTRODUCTION. The distribution of tlie Permo-Carboniferous Echinodermata is equally fitful with that of the Actinozoa, and the life history of this Class would seem to have been governed by the same causes as those which yielded so powerful an influence on the latter. Erom a specific point of view the occurrence of Echinoderms in the rocks in question is rare ; at any rate this would appear to be the case from the geological researches that have so far progressed. In two out of the three groups represented this would also appear to be the case numerically, for the Crinoidea is the only Class in which anything like a redundance of individuals predominated. This fact is only arrived at from the abundance of skeletal fragments in some deposits, chiefly stem joints, any thing like perfect calices, not to speak of the entire organism being rare. In the Carboniferous rocks, or those beds below the Lower Marine Series, several horizons have been discovered at which extensive traces of Crinoid life have been found, chiefly consisting of stem fragments entering into the composi tion of limestones. We are now, for the first time, made aware of the existence in our rocks of the Palaeozoic section of the Echinoidea, whilst the Asteroidea, formerly known from the presence of one species, is now represented by three, and these of large size. So far the Crinoidea are known to occur in the Carboniferous and the Upper Marine Series of the Permo-Carboniferous ; the Asteroidea, in both the Lower and Upper Marine Series, but the Echinoidea only from the Upper Marine Series. The Cystoidea and Blastoidea are not represented at all in our New South Wales Carboniferous or Permo-Carboniferous rocks, although the latter class is known to occur in beds of the last-named age in Queensland. I am not aware that the remains of Annelids have been before noted ; and although the evidence is but meagre, sufficient is before us to raise a hope of future additions. With regard to the Crustacea, two Orders are known to exist—the Ostracoda and Trilobita. The first occurs both in the Carboniferous and Permo-Carboniferous, the second only, so far as I have been able to ascertain, in the second division of this series of our rocks.