676 THE AMERICAN NATURALIST. (Vor. XXXIX. 
lobed organ, rather long and wide; it abruptly enlarges to form 
a bulbous uterus, which narrows to form a rather long, wide 
vagina. The receptaculum seminis is small and spherical and 
connects with the vagina near its opening by a very long, nar- 
row duct. The albuminiparous gland is very large. Nerves as 
in the other species. The uterus is yellowish, the albuminipar- 
ous gland is yellowish brown, the vagina is blackish white, the 
receptaculum is bright red and the other organs are flesh-col- 
ored. 
The genitalia of auricularia do not resemble those of any 
other species very closely. The penis is longer than in any 
other species and the receptaculum is smaller. The uterus is 
more swollen and of a different shape. The prostate resembles 
that of both e/odes and mighelsi. 
Moquin-Tandon's figure in the Histoire Naturelle des Mol. 
lusques Terrestres et. Fluviatiles de France shows the organs of 
different shape and position, but this may be due to viewing 
them in a different position and without separating the organs. 
Lymna@a megasoma Say. 
? No specimens of this Species have been obtainable for dissec- 
tion. Wetherby's description and figure in /our. Cincinnati 
Soc. Nat. Hist., vol. 2, P. 95, show the penis to be rather wide 
and shorter than the penis-sac. The receptaculum seminis is 
ovate-pyriform. The other organs are not very clearly shown. 
COMPARISONS. 
The question has presented itself to the writer as to whether 
the genitalia of Lymnza will afford sufficiently stable data upon 
which to base Systematic groups or subgenera. In the land 
shells these organs furnish, in many cases, excellent characters 
for generic and even family divisions. It is possible that the 
examination of a large number of species might produce tangible 
