ANCYLUS. 223 
4. ANCYLUS DIAPHANUS, Haid. 
Hald. Monog. p. 8, t. 1, fig. 4. 
Ohio and Wisconsin. 
5. ANCYLUS HALDEMANI, Bourguignat. 
Zool. Proc. London, 83, 1853. 
A. depressus (preoccupied), Hald. Monog. p. 6, t. 1, f. 12. 
Tt has not been detected elsewhere than the 
original locality. 
6. ANCYLUS PARALLELUS, Haid. 
Hald. Monog. p. 11, t. 1, fig. 6. 
This species has only been detected in the 
New England States. Prof. Haldeman has 
erred, I think, in considering the A. rivularis 
of Gould’s “Invertebrata of Massachusetts” 
to be the same species, as I can only consider 
the description and figure to refer decisively 
to the rivularis. 
a7) 
