Echinodermata

“A class of radiate animals, the highest in organisation of the great division of the animal kingdom. They have a digestive and a vascular system; for the former, however, there is in many of them only a single orifice; a circular and radiating nervous system has been observed in manyl they are especially characterised by their well-organised skin which in many is strengthened by calcareous plates, and in some also has the additional protection of numerous long spines. a, Asterias Tesselllata (Asteriadae); b, Spatangus (Echinidae) or sea-egg.” — Chambers’ Encyclopedia, 1875

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