region enlarged; that, in the Ophiuran, that region makes one side of the small circular disk; while in the Crinoid it is enlarged and extended to make the calyx-like projection and stem. In the same way, if we place them in the same attitude, we shall see that the long, straight rows of suckers along the length of the Holothurian, and the arching zones of suckers on the spherical body of the Sea-Urchin, and the furrows with the suckers protruding from them along the arms of the Star-Fish and Ophiuran, and the radiating series of pores from the oral opening in the Crinoid are one and the same thing in all, only altered somewhat in their relative proportion and extent. Around the oral opening of the Holothurian there are appendages capable of the most extraordinary changes, which seem at first to be peculiar to these animals, and to have no affinity with any corresponding feature in the same Class. But a closer investigation has shown them to be only modifications of the locomotive suckers of the Star-Fish and Sea-Urchin, but ramifying to such an extent as to assume the form of branching feelers. The little tufts projecting from the oral side in the Sea-Urchins, described as gills, are another form of the same kind of appendage. The Holothurians have not the hard, brittle surface of the other Echinoderms; on the contrary, their envelope is tough and leathery, capable of great contraction and dilatation. No idea can be formed of the beauty of these animals either from dried specimens or from those preserved in alcohol. Of course, in either case, they lose their color, become shrunken, and the movable appendages about the mouth shrivel up. One who had seen the Holothurian only as preserved in museums would be amazed at the spectacle of the living animal, especially if his first introduction should be to one of the deep, rich crimson-colored species, such as are found in quantities in the Bay of Fundy. I have seen such an animal, when first thrown into a tank of sea-water, remain for a while closely contracted, looking like a soft crimson ball. Slowly, almost imperceptibly, as it becomes accustomed to its new position, it begins to elongate; the fringes creep softly out, spreading gradually all their ramifications, till one end of the animal seems crowned with feathery, crimson sea-weeds of the most delicate tracery. It is much to be regretted that these lower marine animals are not better known. The plumage of the tropical birds, the down on the most brilliant butterfly's wing, are not more beautiful in coloring than the hues of many Radiates, and there is no grace of motion surpassing the movements of some of them in their native element. The habit of keeping marine animals in tanks is happily growing constantly more popular, and before long the beauty of these inhabitants of the ocean will be as familiar to us as that of Birds and Insects. Many of the most beautiful among them are, however, difficult to obtain, and