Our few brief descriptions of British anemones and corals have been confined to those species which appear in our coloured plates, but we have interspersed here and there between the text a few illustrations which will assist in the identification of other species and also help to show what a rich variety of form is exhibited by these beautiful creatures. Some of these inhabit deep water only and are consequently beyond the reach of most sea-side observers during the ordinary course of their work; yet they may often be seen in fishing villages, especially in the south-west, where they are frequently brought in among the haul of the trawlers, attached either to shells or stones; and live specimens of these deep-sea anemones may even be seen on the shells of whelks and bivalve molluscs in the fishdealers' shops of London and other large towns. [Illustration: FIG. 102.--_Sagartia parasitica_] One of the species in question--the Parasitic Anemone (_Sagartia parasitica_) is generally found on the shell of the whelk or some other univalve; and, if removed from its chosen spot, it will again transfer itself to a similar shell when an opportunity occurs. This interesting anemone is usually seen among the dredgings of the trawler, but may be occasionally met with on the rocky coasts of the south-west, at extreme low-water mark. Though sometimes seen attached to stones, shells may undoubtedly be regarded as constituting the natural home of the species, and many regard the former position as accidental or merely temporary, and denoting that the animal had been disturbed and removed from its favourite spot, or that circumstances had recently rendered a change of lodgings necessary or desirable. Further, the shell selected by this anemone is almost always one that is inhabited by a hermit crab; and this is so generally the case that the occasional exceptions to the rule probably point to instances in which the occupant of the shell had been roughly ejected during the dredging operations. [Illustration: FIG. 103.--THE CLOAK ANEMONE (_Adamsia palliata_) ON A WHELK SHELL, WITH HERMIT CRAB] The peculiar habit of the anemone just referred to makes it an interesting pet for the aquarium, for if removed from its natural home, and placed in the aquarium with a hermit crab, it will, sooner or later, as the opportunity occurs, glide from its hole on the stone or rock, and transfer itself to its favourite moving home. It may be difficult at first to see what advantage can accrue to the anemone by the selection of such a situation; and, moreover, it becomes an interesting question as to whether the advantage is a mutual one. Close observations may, and already have, thrown some light on this matter, though it is probable that there still remains something to be learnt concerning the relations which exist between the inside and outside occupants of the portable house.