THIRTEENTH REPORT. 
Polygyra mnltilincata (Say). 
alba (Witt.). 
rubra Witt.). 
palliata (Say). 
pcnn sylvan ica ( Green ) . 
profunda (Say). 
alba (Walk.). 
sayana Pils. 
thyr oides (Say). 
tri dentate (Say). 
zaleta (Binn.). 
Strobilops affinis Pils. 
la byrintJiica ( Say ) . 
virgo (Pils.). 
Pupoides marginatus (Say). 
B i fid a via a rm if era ( S ay ) . 
affinis Sterki. 
similis Sterki. 
clappii Sterki. 
contra eta (Say). 
corticaria (Say). 
pentodon (Say). 
tappaniana (G. B. Ads.). 
Papilla muscorum (L.). 
Vertigo bollesiana (Mse.). 
gouldii Binn. 
milium Ged. 
morsel Sterki. 
oral a Say. 
tridentata Wolf. 
ventricosa ( Mse. ) . 
elatior Sterki. 
Cochlicopa lubrica (Moll.). 
Ci rci naria con ca va ( Say ) . 
Omphalina fuliginosa (Griff.). 
inornate (Say). 
Vitrina limpida Gkl. 
Vitrea binneyana ( Mse. ) . 
ceUaria (Mull.). 
ferrea (Mse.). 
hammon is ( Strom) . 
indent atfi (Say). 
nmltidenta ta ( Say ) . 
rhoadsi Pils. 
wheatley i (Bid.). 
Eucomilus chcrsinus polygyratus Pils. 
fulfils (Mii 11.). 
Zonitoides arborca (Say). 
exigua (Stimp.). 
lima tad a (Ward) . 
milium (Mse.). 
minusciila ( Binn.) . 
nitida (Moll.). 
