The Inhabitants of the Aquarium 307 



four threadlike feelers, one long and one 

 shorter pair, which on their inner base bear 

 the eyes. The so-called foot with which 

 they move, is short and blunt at the ends; 

 it is like the rest of the body, of a velvety 

 black or brownish red color. The shell is 

 flat, disk-shaped, and consists of five or six 

 spiral winding's, small in the center and in- 

 creasing in diameter toward the outside. 

 Its color is a dark brown. The Trumpet 

 Snail as well as the other members of the 

 family are true hermaphrodites ; in other 

 words, the sexual organs of both sexes are 

 represented in one and the same individual. 

 But to effect propagation a mating process 

 between two snails takes place and is indis- 

 pensable as the location of the sexual organs 

 in the individual excludes the possibility of 

 impregnation without the co-operation of a 

 mate. This snail propagates well in the 

 aquarium. 



The Swamp, or Mud Snail (Limncea palus- 

 tris), can easily be distinguished by the reg- 



