KEY TO THE CLASSES OF LAND AND FRESH-WATER 



MOLLUSKS 



Without a shell or with a cap-like or spirally wound, one-piece shell; 

 usually with a head hearing eyes and tentacles and with a broad, flat 

 foot; aquatic or terrestrial 



Class Gastropoda Snails and Slugs 

 With a bivalve shell; no head bearing eyes and tentacles; foot usually 

 keel-like; aquatic 



Class Pelecypoda Clams and Clam-like MoUusks 



KEY TO SOME REPRESENTATIVE SPECIES OF THE COMMON 

 GENERA OF SNAILS AND SLUGS 



1. Water animals; with only one pair of tentacles; never with eyes at the 



ends of the tentacles 2. 



Land animals; with one or two pairs of tentacles 93. 



2. Shell cap-like, not coiled — Limpets 3. 

 Shell more or less coiled 9. 



3. Apex pink; about %" 



Rhodacmea filosa (Conrad) 

 Shell almost uniformly brownish 4. 



4. Apex about central; about %"; western states 5. 

 Apex more posterior; shell smaller 6. 



5. Shell fairly solid and about as high as wide 



Lanx patelloides (Lea) 

 Shell thinner and more depressed 



Lanx ('Wal\erola) ?^/amathensis Hannibal 



6. Apex cut oif internally from the rest of the shell by a septum, appearing 



externally like a small shell-cap 7, 



Apex not so separated 8. 



7. Apex with radial striations 



Gundlach-ia mee\xana Stimpson 

 {Kincaidella mee\iana (Stimpson) ) 

 Apex smooth 



Gundlachia hjalmarsom Pfeiffer 



8. Apex smooth 



Ferrissia diaphana (Haldeman) 

 {Laevapex fusca (Adams) ) 

 Apex with radial striations 



Ferrissia rivularis (Say) 

 (Ancylus rivularis Say) 



9. Shell subconic, scarcely coiled; with a thin columellar plate projecting 



across part of the aperture; Alabama 



Amphigyra alahamensis Pilsbry Boat Shell 

 Shell with two or more coils; no columellar plate across the aperture 10. 



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