188 GLAUCUS; OE, 



tlie tongue of the little shell-fish ; a description of its 

 extraordinary mechanism (too long to quote here, but 

 which is well worth reading) may be found in Gosse's 

 "Aquarium."* 



A pra^vn or two, and a few minute star-fish, will 

 make your aquarium complete ; though you may add 

 to it endlessly, as one glance at the salt-water tanks 

 of the Zoological Gardens, and the strange and beau- 

 tiful forms which they contain, will prove to you 

 sufiiciently.-f* 



You have two more enemies to guard against ; dust, 

 and heat. If the surface of the water becomes clogged 

 with dust, the communication between it and the 

 life-giving oxygen of the air is cut off ; and then your 

 animals are liable to die, for the very same reason 

 that fish die in a pond which is long frozen over, 

 unless a hole be broken in the ice to admit the air. 

 You must guard against this by occasional stirring 

 of the surface, (it should be done once a day, if pos- 



* P. 34. Figures of it are given in Plate VIII. 



t Remember always, moreover, that if you cannot procure these 

 animals yourself, you may get them all, and more, from my friend, 

 Mr. Lloyd; of Portland Road. 



