94 LIMNAA. 
general form appears to approach my L. Gabbii. 
The latter, however, is rather more robust, 
and has no umbilical opening. 
_ 
Subgenus BULIMNEA, Haldeman. 
8. LIMNAZA MEGASOMA, Say. 
Hald., p. 18, t..3, figs. 1, 3. 
Inhabits from Lake Champlain westward in 
the great lakes to’ Michigan. 
Subgenus LIMNOPHYSA,, Fitzinger. 
"Shell large, narrow, with elevated spire. 
tT 
9. LIMNEA REFLEXA, Say. 
Hald., Monog., 26, t. 8. 
LL. umbrosa, Say, Hald. Monog. 24, t. 7, figs. 1, 2, 3, 6, 7, 8. 
L. zebra, Tryon, Plate 16, fig. 14. 
I have concluded, after careful study of a 
large series of specimens, that my L. zebra 
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