Seashells from Manuel Antonio (Costa Rica)

[rafa]

I send again seashells from Costa Rica. I can't identificate its. Could somebody help me please?
Thanks.
<a href="http://www.badongo.com/pic/2968465" target="_blank"><!-- m --><a class="postlink" href="http://www.badongo.com/pic/2968465">http://www.badongo.com/pic/2968465</a><!-- m --></a>

[paul monfils]

There are shells here from three different families. #1,2 and 4 - Siphonariidae; #3 - Fissurellidae (at least 2 species); #5 and 6 - Lottiidae. Too much wear to ID them to species level with any degree of confidence.