Hydroids and polyzoans are often gathered and preserved as seaweeds.
Spider-crabs (Maa), for example, have their carapaces covered with alg and hydroids of all sorts.
Hydroids are colonies of associated animals living a communal life.
Found at extreme low-water mark on hydroids, shells, stones, and Fucus.
Found creeping like a small dodder-plant over other polyzoans, hydroids, and seaweeds.
They are covered with hairs, and sometimes have planted on their backs alg, hydroids, and even barnacles.
From these hydroids are created the transparent jelly-fish we see floating in the ocean.
Under the same instruction ten lessons were given on the use of the microscope and the preparation of specimens of hydroids.
There is also another general feature in which the Tubularians differ from both the other groups of Hydroids.
This species, which is found on the Pacific coast, is perhaps the most beautiful of the hydroids.