60 



THE FAMILY AQUAKIUM. 



The Planorhis Armigerus is common in the swamps and 

 ponds of every portion of this State. The P. trivolvis is 

 common to most of the northern and western States. It 

 is a pale yellow, and is twisted up like a ram^s horn. The 

 P. hicarinatus is abundant here in every sluggish stream. 

 The Physa heterostrojpha is a pretty snail, yellowish, or a 

 greenish yellow, in color. The Paludina dioscisa is a snail 

 to be obtained without difficulty. 



These mollusca would present quite as large an assort- 

 ment for an ordinary Aquarium as would seem desirable. 

 As long as too great a number of them were not placed 

 in the tank together, they would not interfere with the 

 general harmony of the community of which they formed 

 a part. If rendered so numerous as to make their usual 

 food insufficient in its supply, perhaps they, too, might 

 be tempted to turn destroyers ; but that would be the 

 result of their protector's negligence, not of their own vora- 

 city. On the other hand, these snails breed rapidly in a 

 tank, but the fish have an excessive appetite for their 

 young, and if permitted, will devour them as rapidly as 

 they appear. It would be judicious, therefore, to remove 

 the spawn, occasionally, to a jar containing healthy plants, 

 whence they could be transferred to the tank when suf- 

 ficiently matured. 



The Fresh-water Mussel (Unio radiatus)^ as well as 

 the Anodon fluviatilis^ another neat mussel, would not be 

 out of place in a perfect Aquarium. The mill-ponds and 

 dull streams, here and to the eastward, will supply them. 



