33 



Var. elatior Sterki. Larger and more elevated 

 than ventricosa, with a rather acute apex ; a 

 strong callus in the palate, into which the 

 palatal plicae merge, a strong, tooth-like 

 lamella in the base. Although rather different 

 from ventricosa, it seems to be connected by 

 intermediate specimens. Seen from New 

 York, Ohio, Michigan and West to Montana, 

 while the type is found in the eastern part of 

 country. 



33. Vertigo tridentata Wolf. Rather scarce. 



34. Vertigo {Angustula) milium Old. Rather 



common. 



35. Cochlicopa luhrica Mull. (Cionella. Ferussacia, 



subcylindrica Lin.) Not common. 



36. Circinaria concava Say. {MacrocycUs c.) Rather 



common. 



37. Hyalinia fuliginosa Griffith. Scarce. 



38. Hyalinia hammonis Stroem (radiatula Aid., 



electrina Gld.) Common. Most specimens 

 are mature before winter. 



39. Hyalinia wheatleyi B\6. Rather scarce. 



40. Hyalinia — ? Near hammonis and wheatleyi ; 



but seems to be distinct. Seen also from the 

 southern Alleghanies and from Texas. One 

 specimen near Midvale Station. 



41. Hyalinia indentata Say . Rather common. 



42. Hyalinia ferrea Mse. Very rare ; Midvale. 



43. Hyalinia milium Mse. Common. 



44. Zonitoides* exignus Stimpson. Common. 



45. Zonitoides minusculus Binney. Rather scarce. 



46. Zonitoides leeviusculus Sterki. Rare. About a 



dozen dead shells were found in drift on the 

 river after the high water of 1898. This is 

 the most eastern known station of this 

 species. 



*Since the anatotiiy of this and tlie two following species is not 

 known, their ranging under this genus nia.y be doubled. .And 

 so it i'j with No. A'^ which is ranged with Hy. feri-ea for the 

 sinfiilar ippearance of its shell. 



