The Sea Anemone, which has already provided us with objects for our microscope, has many near relatives which we must make a point of examining, while we have the opportunity. Many of these creatures, or rather their colonies, for they do not live singly, are to the naked eye, strangely like seaweeds. A number of them are moss-like and may be found on wooden breakwaters and similar situations when the tide is low; they should be collected and examined and, to see them at their best they should be examined under water. It is hardly necessary to describe any one of these colonies in detail, for they are so numerous that the one we described might not come into the hands of our readers for a long time. In general characters they are all somewhat similar so we will confine ourselves to generalities. For the most part, the stems and branches of these colonies are of the thickness of thread. As we watch them under the microscope we shall see that they are studded with little cups and, presently, from each little cup there appears a little tuft of tentacles which is waved about in the water. Each member of the colony is similar to its neighbour and each one, again, is very like the fresh water _Hydra_ with which we are familiar. Of all the common objects of the sea shore one of the commonest everywhere is the sea-mat. Nine people out of ten or, we might safely say that everyone who had not learned its true nature, would guess it to be a seaweed. As we find it washed up on the beach it is almost the colour of sand, somewhat rough to the touch, whilst its whole surface is pitted with minute holes. The sea-mat, when dry as we usually find it, is a remnant of a colony of sea dwellers very similar to those we have just described. From each little hole, in a living specimen, which we can find without much difficulty, there appear the familiar tentacles; each hole is the home of a minute hydra-like animal.