ANIMAL LIFE IN THE MARINE AQUAKIUM. 105 



ignoble but important part of scavengers, and cannot be 

 dispensed with. Thej devour the refuse of decaying 

 plants, and decomposing animal substances. They also 

 feast upon the millions of spores, or seeds, of the Algae, 

 held in suspension at times by the water. In this manner 

 tbaj are enabled, if sufficiently numerous, to keep the tank 

 in a cleanly condition, and deliver us from all that might 

 interfere with a good view of our cherished favorites. 



The Periwinkle {Littorina littorea) is a sea snail, that 

 they boil and eat in England, as we boil and eat chest- 

 nuts in this country. It is as popular among children 

 there, and as common in the theatres, as peanuts are here. 

 The periwinkle may be gathered everywhere on our sea- 

 shores, and is one of the Aquarium's most valuable ad- 

 juncts. The decaying vegetation is its natural food. It 

 rejoices in a multitude of colors, from a dull grey up to 

 orange, red, and even bright scarlet, and indulges occa- 

 sionally in black bands. The small, yellow kind are not 

 to be depended upon as thoroughly as the rest. 



The Winkle {Pyrwla canaliculata) is a common shell 

 upon all our coasts. It is hardy, and can be sustained for 

 months in a tank. 



The Sea Hares {Aj)lysice) should not be omitted, when 

 they can, without much difficulty, be secured. The A. 

 hyhrida succeed well in European Aquaria, and its con- 

 geners might with us. The A. leporince of the Mediter- 

 ranean is said to have supplied the poison with which 

 Locasta terminated the intrigues of Nero's enemies, as 



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