First post, identification help needed!!

[shellnut 09]

Ok, so I am a student currently working on a General Biology project that deals with identification of shells.

Heres what we are working with:
<img src="http://i77.photobucket.com/albums/j62/ChaseA17/Shells3.jpg" alt="http://i77.photobucket.com/albums/j62/ChaseA17/Shells3.jpg" style="border:0" />
<img src="http://i77.photobucket.com/albums/j62/ChaseA17/Shells2.jpg" alt="http://i77.photobucket.com/albums/j62/ChaseA17/Shells2.jpg" style="border:0" />
<img src="http://i77.photobucket.com/albums/j62/ChaseA17/Shells1.jpg" alt="http://i77.photobucket.com/albums/j62/ChaseA17/Shells1.jpg" style="border:0" />

Any help in taxonomically identifying these shells or a good way to start working macro>micro level in naming would be greatly appreciated.

Thanks!

Shellnut 09 in Florida