BRYOZOAN 

These colonies of animals live on the underside of rocks. Each branch of the tube is an individual animal. The delicate tentacles can barely be seen in the photo on the lower left, but these tentacles are used to push a stream of water into the mouth. The water is filtered for organic matter and past out again. The entire colony on the left covers an area of about 2 cm. in diameter. The diameter of the tentacle ring in the lower photo is a little less than .5-mm.