1 — Cylindrical or elongated fusiform-conical, with elongated 



body -whorl and aperture; polished; 6x2.5 mm. 



Genus COCHLICOPA 23 



2 — Cylindrical or elongated conical, with short body-whorl 



and rounded aperture; less than 5x1,5 mm. 



* — Peristome sharp, aperture circular, whorls numerous, 

 narrow, shell distinctly cylindrical, aperture un- 

 armed. Genus SPHYRADIUM 24 



**-Peristome more or less refiexed or expanded, aper- 

 ture more or less armed with teeth or folds. 



i — Aperture with one columellar fold; shell minute, 

 white, with oblique whorls. Genus CAEYCHIUM 25 



ii — Aperture usually variously armed with teeth; no 



columellar fold, 

 o — Teeth none, or one (rarely two) on parietal 

 wall only, shell more than 3 mm. long. 

 Conical, aperture without teeth, peristome 



thickened and reflexed. Genus PUPOIDES 26 

 Subcylindrical, peristome scarcely reflexed; 

 aperture usually armed. Genus PUP ILL A 27 

 oo-Teeth usually on both the parietal wall and 

 peristome ; shell less than 3 mm. long. 

 "Whitish or horn colored, with a double or 

 furcate parietal tooth; if brownish only 

 parietal tooth present. Genus BIFIDAEIA 28 

 Brownish or brown, teeth various, on both 

 walls of aperture. Genus VERTIGO 29 



3 — Depressed conical or flattened. 



* — Peristome sharp, or slightly thickened. 



i — Shell longitudinally ribbed or striate ; surface dull. 

 0 — Minute, less than 2 mm. in diameter. 



Genus PUNCTUM 30 

 oo-Larger, more than 5 mm. in diameter. 



With continuous spiral colored band; loess 



fossil. Genus OREOHELIX 31 



Colored bands absent, or interrupted. 



Genus PYRAMIDULA 32 

 ii — Shell horn colored, or if brown, polished, 

 o — Diameter more than 20 mm. 



Genus CIRCINARIA 33 

 co-Diameter less than 10 mm. 



Shell compact-conical, whorls narrow. 



Genus EUCONULUS 34 

 Shell more or less depressed. 



Spire very flat, whorls narrow, umbilicus 

 very wide, aperture with small teeth or 

 folds. Genus HELICODISCUS 35 



77 



