Description: English: An early stage in the development of Antedon, showing the foot-plate or “dorso-central” fp at the end of the stem col. Some of the thecal plates, infrabasals I B, basals B, and orals O are forming around the body-cavities r.pc and l.pc; p is the water-pore. (After Seeliger.). Date: 1911. Source: Encyclopædia Britannica, 1911. Author:
Encyclopædia Britannica, Volume 8, Slice 10., available freely at
Project Gutenberg.