THE NAUTILUS. 51 



Polygyra tridentata Say. Variety, region of the mouth much 

 compressed and very deeply striated. 



Polygyra inflecta Say. A few broken specimens. 



Polygyra profunda Say. Very large well-preserved shells, heavy, 

 and bands very plainly marked. 



Polygyra albolahn's Say. Very scarce. 



Polygyra exoleta Binn. Common and of usual form. 



Polygyra imdtilineata Say. Perhaps about the most plentiful of 

 all the species found. This shell has never been found alive within 

 twenty miles of this deposit. 



Polygyra palliata Say. 



Polygyra apprcssa Say. Several broken specimens. 



Polygyra elevata Say. Fairly common and well preserved. 



Polygyra pennsylvanica Green. Quite common in the deposit, 

 but rare in this vicinity ali^-e, only ten or twelve specimens having 

 been found in the last six years after careful search. 



Polygyra thyroides Say, Good specimens and fairly common. 



Polygyra mitchelUana Lea, Common in the deposit, but rare and 

 very local alive, only one locality known near Lawrenceburg. 



Polygyra stenotrema Fer. 



Polygyra monodon Rack. Very rare. 



Pupoides margiiiatus Say. 



Bijidaria contracta Say. 



Bifid aria armifera Say. Common. 



Cochlicopa luhrica Mull. A few broken specimens. 



Circinaria concava Say. Quite common. 



Vitrea hammonis vStrom. Several broken shells. 



Gastrodonta ligera Say. Common and in good condition. 



Pyramidtda alternata Say. Very large forms with distinct and 

 beautiful color markings. 



Pyramidula solitaria Say. Plentiful, large, heavy shells. 



Pyramiditla persfiectiva Say. Rare. 



Pyramidida striatella Anth. Rare. 



Helicodiscus linearis Say. Rare and broken. 



Succinea sp. Very large, quite common, and in fine condition, 

 nothing nearly as large found here alive. 



Pomatiopsis lapidaria. Common. I have never taken this shell 

 alive in the vicinity of Lawrenceburg. 



Subsequent search will no doubt increase the numbers of this list, 



