This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
PTRS . Porania antarctica SmithE Smith Smith Smith LjungmanLjungman Smith Smith Smith Smith disc with arm from below disc from above interambulacral plate Philosophical Transactions of the Royal Society An Account of the Petrological Botanical and Zoological Collections Made in Kerguelen's Land and Rodriguez During the Transit