GENERAL HISTOLOGY

Detailed explanation-1: -Sea lilies are permanently attached to the substrate by a stalk, while feather stars (shown above) are swimming or crawling animals that can attach to the substrate using a ring of claw-like projections. Note that unlike other echinoderms, the oral surface of sea lilies and feather stars is directed upward.

Detailed explanation-2: -Sea lilies and feather stars are examples of Crinoidea.

Detailed explanation-3: -Crinoidea. The crinoids, such as the sea lilies and feather stars, are considered to be the most primitive of the echinoderm species.

Detailed explanation-4: -Stalked crinoids, commonly known as sea lilies, have a relatively long, stem-like stalk composed of many stacked disk-shaped ossicles. The stalk attaches the organism to the sea floor and raises the body off of the bottom and into the current where it can feed.

Detailed explanation-5: -The sea lilies are crinoids, when they are in their adult form, they are attached to the sea bottom by the stalk. They usually have five or more than five arms. They have a stem which is attached to them to the substrate by the large and terminal disc or by branching, irregular radicular at the bottom of the stem.