A better photo and request for identification

[wil9000]

Here is a better photo of a shell that I asked for help with earlier, this time inside and outside.
<a href="http://www.flickr.com/photos/wil9000/4861227582/" target="_blank"><!-- m --><a class="postlink" href="http://www.flickr.com/photos/wil9000/4861227582/">http://www.flickr.com/photos/wil9000/4861227582/</a><!-- m --></a>

Also, there's this clam:
<a href="http://www.flickr.com/photos/wil9000/4860606897/" target="_blank"><!-- m --><a class="postlink" href="http://www.flickr.com/photos/wil9000/4860606897/">http://www.flickr.com/photos/wil9000/4860606897/</a><!-- m --></a>
I have no clue about it.

And, there's this clam, only one half. The third picture shows how huge the hinge is.
<a href="http://www.flickr.com/photos/wil9000/4860607169/" target="_blank"><!-- m --><a class="postlink" href="http://www.flickr.com/photos/wil9000/4860607169/">http://www.flickr.com/photos/wil9000/4860607169/</a><!-- m --></a>
<a href="http://www.flickr.com/photos/wil9000/4861227420/" target="_blank"><!-- m --><a class="postlink" href="http://www.flickr.com/photos/wil9000/4861227420/">http://www.flickr.com/photos/wil9000/4861227420/</a><!-- m --></a>
<a href="http://www.flickr.com/photos/wil9000/4861227264/" target="_blank"><!-- m --><a class="postlink" href="http://www.flickr.com/photos/wil9000/4861227264/">http://www.flickr.com/photos/wil9000/4861227264/</a><!-- m --></a>

Thank you again. You guys are amazing!