Neocrinus decorus, like most echinoderms, is composed of
numerous calcite plates which are arranged into different
organs. N. decorus is divided into 3 sections: - The stem: -
raises the calyx and arms above the sediment and is composed of
a stack of numerous 5-sided star-shaped plates. - bears
flexible, finger-like appendages called cirri that are used to
reattach itself to the substrate after moving. - The calyx (body
or theca): - is formed of 2 bands of 5 plates that form a cup-
shaped body, from which the bases of the arms arise. - is
covered on top by numerous small polygonal plates. The mouth and
anus are found on this surface. Neocrinus decorus calyx with
mouth, food groove and anus. - 5 originate in the calyx but
these frequently divide, similar to tree branches, so that there
may be up to 40 arms in total. - are formed of stacks of
U-shaped calcite plates - bear numerous projections called
pinnae (like those of a fern frond). It is on these pinnae that
tube feet, covered in mucus, extend into the wate