A third level can be defined to identify a particular host server at the Internet address. In our example, www is the name of the server that handles Internet requests. (A second server might be called www2.) A third level of domain name is not required.
Sea anemones are a group of water-dwelling, predatory animals of the order Actiniaria. They are named for the anemone, a terrestrial flower.Sea anemones are classified in the phylum Cnidaria, class Anthozoa, subclass Hexacorallia. sea anemone is a sessile polyp attached at the bottom to the surface beneath it by an adhesive foot, called a basal disc, with a column-shaped body ending in an oral disc.
Most adult tunicates are sessile and are permanently attached to rocks or other hard surfaces on the ocean floor; others, such as salps, doliolids and pyrosomes, swim in the pelagic zone of the sea as adults. Various species are commonly known as sea squirts, sea pork, sea livers, or sea tulips. multitaxon molecular study in 2010 looked for evidence that sea squirts are descended from a hybrid between a chordate and a protostome ancestor, and for evidence of sea urchin-tunicate hybridization in the genes of modern sea squirts.