42 THE CHICAGO ACADEMY OF SCIENCES. 
which enter the foot or other outlying parts of the Limnza proceed 
no further.” 
The genitalia of Galba palustris from Braddocks Bay, N. Y., has 
been observed to be infested with thousands of a small parasite. These 
cases were all confined to individuals with malleated shells. It is 
probable that many of the American Lymneas offer hosts for early 
stages of worms, but this subject does not appear to have been given 
much attention by American zoologists. 
h. FOOD. 
The normal food of the Lymnzeas is vegetal; this, however, varies 
according to circumstances or individual preference. That the family 
is carnivorous at nearly all times is proven by the following table. 
Deviations of Lymnza from plant food.* 
Authority. Species. Food. 
Semper* stagnalis Living newt (plenty of plant food accessible). 
Ullyet? stagnalis Living Stickleback. 
Cockerell® stagnalis Old fish head. 
Cockerell* stagnalis An old newspaper. 
Baker® palustris Dead carcasses of dogs, cats, etc. 
Sterki® palustris A live leach. 
Brockmeier* peregra Plankton caught in mucus trap. 
Cooke? stagnalis Dytiscus larvae, snails, minnows. 
It would appear that many Lymnzas adopt a flesh diet from 
choice. Semper® cites the case of several confined Lymnzas in which 
they attacked healthy living specimens of a large water newt (Triton- 
teniatus) and after overcoming them, devour them with evident relish, 
although there was an abundance of their favorite vegetable food 
growing near them. Living minnows have also served as an animal 
diet by preference.® 
The vegetable food of Lymnzea consists largely of conferve, the 
stems of water plants, diatoms, desmids, spirogyra and other pond 
scums. It is believed by some conchologists'® that the absence of vege- 
table food is the cause of the well-known habit in Lymnza of eating the 
shell of its fellow captives when in captivity. Mr. Walter’s remarks 
on the food of these animals are so pertinent that they are repeated 
below : 
1After Walter, Cold Spring Harbor Mon., VI, p. 21. 
2Cited by Cooke, Moll., p. 34. 
sCooke, p. 37. 
4Science Gossip, 1883, p. 1638. 
5Moll. Chi. Area, p. 285. 
®Nautilus, V, p. 94. 
™Forsch.-Ber. Biol. Stat., Plon. Th. 6, p. 165. 
8Animal life, p. 59. 
*Cooke, p. 37. 
*Clessin, Nach. Mal. Ges., V, p. 28, 1873. 
