The Balanced Aquarium and the Snailery 



arrangement of the individual zooids, which looks somewhat 

 like coral. It is found attached to eel-grass and to wharf piles. 



Sea Squirts are globular, gelatinous creatures that send out 

 a jet of water when disturbed. They will live and multiply in 

 the aquarium. 



Snails of the periwinkle group (Littorina) are scavengers. 

 They eat decayed vegetable matter, and pick up the crumbs 

 dropped by fishes. The Dog Whelk (Nassa trivittata) helps at this 

 job of cleaning, and he is an ornament to the tank. But he may 

 drill a hole in the shell, and suck the life blood of your favourite 

 bivalve, reminding you that he prefers fresh to stale food. Be- 

 ware the Whelk (Buccinum), the Moon Shell (Natica), and the 

 Drill (Urosalpinx), for they will slay without mercy every bivalve 

 you put within their reach. 



Hydroids, microscopic creatures of exceeding beauty of 

 form, often mistaken for delicate seaweeds, occur in the aquarium 

 as if spontaneously, attached to the glass sides or to objects inside. 



Hermit and horse-shoe crabs, prawns and little blue crabs 

 should be kept in separate jars. They are most interesting and 

 beautiful. But they are too hungry and too selfish to share the 

 quarters of better-mannered creatures. 



Do not attempt to put into one jar at one time any such 

 number and variety of plants and animals as I have described. 



Understock, rather than overstock, the aquarium. 



Put in fresh water, as evaporation lowers the level. 



Feeding the Animals. — Mince a fresh clam or oyster and 

 feed the sea anemones and corals, by holding a bit on the end of 

 a sharp stick in front of the disk, where the tentacles can reach 

 it. They take it eagerly. The juice lost to the water will feed 

 the bivalves. Cease to offer it, when food is no longer taken. 

 Feed regularly. Bits of meat or clam are good food for the car- 

 nivors, which cannot be trusted in the general aquarium. 



Cleaning the Aquarium. — Dust may be removed from the 

 surface of the water by skimming with pieces of clean white 

 blotting paper. If dead leaves foul the water, put in more water 

 snails, found among decayed leaves on the edges of ponds and 

 ditches. Slime-covered corners of the same pond furnish you 

 the kind of snail which will clean the scum oflF the sides and sur- 

 face of youf tank quickly. There are marine snails that will 

 do the same work in the salt water aquarium. When such means 



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