ANCYLUS. 223 



4. ANCYLUS DIAPHANUS, HaU. 

 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. 



It has not been detected elsewhere than the 

 original locality. 



6. ANCYLUS PARALLELUS, ffald. 

 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 " Livertebrata of Massachusetts " 



to be the same species, as I can only consider 



the description and figure to refer decisively 



to the rivularis. 



(17) 



