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Let us give a glance now at the animals which inhabited the waters of this period. In the Radiates we shall not find great changes; the three classes are continued, though with new representatives, and the Polyp Corals are increasing, while the Acalephian Corals, the Kugosa and Tabulata, are diminishing. The adjoining wood-cut represents a characteristic Crinoid of the Carboniferous age.
Among the corals, the palaeozoic 'Tabulata' are constructed on precisely the same type as the modern millepores; and if we turn to molluscs, the most competent malacologists fail to discover any generic distinction between the 'Craniae', 'Lingulae' and 'Discinae' of the silurian rocks and those which now live.
Among the corals, the palaeozoic 'Tabulata' are constructed on precisely the same type as the modern millepores; and if we turn to molluscs, the most competent malacologists fail to discover any generic distinction between the 'Craniae', 'Lingulae' and 'Discinae' of the silurian rocks and those which now live.
In this sense the Millepores are in our epoch the representatives of those early Corals called by naturalists Tabulata and Rugosa, distinguished from the Polyp Corals by the horizontal floors, waving in some, straight in others, which divide the body transversely at successive heights through its whole length, and also by the absence of the vertical partitions, extending from top to bottom of each animal, so characteristic of the true Polyps.
These transverse beams or floors must not be confounded with the horizontal floors alluded to in a former article as characteristic of the ancient Acalephian Corals, the Rugosa and Tabulata.
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