526 



Phylum Mollusc a 



sp., prefer decaying to fresh lettuce. In the case of the first two species 

 the excess need not be removed but the amount given at each additional 

 feeding is reduced to a minimum, the pieces of fresh lettuce being 

 reduced to the size of a pea; these pieces should soften and decay after 

 they are in the aquarium. The vascular parts of the lettuce are the most 

 satisfactory for this purpose; these pieces normally do not become 

 covered with long filaments of mold and any which become moldy should 

 be removed. Should a snail refuse dead leaves and if no decaying 

 lettuce is available, the leafy part of fresh lettuce may be cut into narrow 

 strips with a pair of scissors, thus insuring softening of the tissue 

 sufficiently to afford a satisfactory food ; under such conditions the snails 

 will usually eat the lettuce at once. 



When an aquarium is stocked with newly hatched snails, usually a 

 millimeter or less in diameter, it is not necessary to start them in small 

 aquaria in order to prevent losses. The aquarium should be prepared 

 24 hours prior to the introduction of the snails and food, except for the 

 dead leaves which are introduced at the time the aquarium is set up. 

 The lettuce, of which a very small amount is necessary, should be cut 

 into narrow strips with scissors. When the snails are introduced it is 

 necessary to see that they fall on the dead leaves which give them an 

 immediate food supply. The aquarium should not be disturbed sub- 

 sequently for at least 48 hours. 



The food habits of snails of the same species may vary in different 

 aquaria; this is especially noticeable in the case of Fossaria modicella 

 and F. m. rustica. Some snails seem to be influenced by the seasons in 

 the amount and kind of food they prefer. 



Aquaria should never be kept in sunlight but in subdued light. 



REARING TERRESTRIAL SNAILS 



Wendell Krull, U. S. Bureau of Animal Industry 



A RECTANGULAR terrarium about 18" x 9" x 10" is ideal in size. 

 Cover the bottom with an inch of gravel and then add soil to a 

 depth of 2 inches at one end to 5 or 6 inches at the other, making a 

 sloping contour. Cover the surface of the deeper half with several 

 layers of dry leaves; a few small dry sticks covered with bark are 

 desirable in a terrarium of this size or larger. Allow the terrarium to dry 

 out thoroughly and let it stand several weeks before using. When it is 

 ready for use cover the gravel with water, pouring it into the terrarium 

 at one corner; a small amount of water should be kept in the gravel at 

 at all times. The terrarium is ready for use when the soil has become 

 moist, it should be covered with a glass plate leaving air spaces on all 

 sides. The soil should remain moist in the aquarium subsequent to the 



