tive appearance, they will not live long in captivity; they presently begin to decay, and slough off in slimy membranous shreds, filthy to look at, and hurtful to the living creatures. The Fuci live pretty well, but their sliminess and ugliness are fatal to their pretensions. From the Red and the Green Orders we must make our selection.
Of the former these will be found good. Rhytiphlæa pinastroides, the Polysiphoniæ, Corallina officinalis, Delesseria alata, Chondrus crispus, Phyllophora rubens (this, especially when dredged from deep water, is one of the very best), the Griffithsiæ, and some of the Callithamnia.
Of the Green weeds Codium tomentosum does pretty well, and affords food for some Mollusca that will eat nothing else. The Cladophoræ are good; Bryopsis plumosa, a most elegant little plant, flourishes in confinement; and Ulva latissima is probably the best of all sea-weeds for our purpose, and is one of the most easily procured on every shore.
The pieces of rock to which the plants are attached should be as clean as possible. All adhering sponges, in particular, should be carefully scraped off, unless they are wanted for immediate examination; as they are sure to die, and corrupt the soil and water with sulphuretted hydrogen, a most nauseous and noxious gas, which turns everything black with which it comes into contact.
Animals.—Of the animals which thrive best in an Aquarium (speaking, of course, only from my own limited experience and observation) the following may be mentioned. The small Sticklebacks (Gasterosteus),
