What are these?  I think the lower one is part of the Cypraeidae family (glossy, brown/beige/tan), but the top one doesn't fit any of the families listed on the family ID site.  
http://www.badongo.com/pic/3026197
http://www.badongo.com/pic/3026229
Do these have common names?
North Shore Oahu is certainly not a seashell heaven, but these are very different from what I regularly found on the East Coast of the US.
Sorry for the pictures; will try to do better next time.  I think it needs a flash.    
Thanks for your help!!

Hi there. Top shell is Drupa ricinus the Prickly Pacific Drupe, widespread in the Indo-Pacific region.
Lower shell is Cypraea caputserpentis caputophidii, the Hawaiian Snake's-head Cowry. This subspecies is endemic to Hawaii, and I believe it is being raised in status to a full species.
Dave

Yep, I googled the prickly pacific drupe and I see it--this one is worn, but still has a green tone to it and snaggly teeth.  I just got back from walking on the beach and found another of the cowrie.  They must be pretty common here.
A whole new world of seashells for me!  Mahalo plenty for your help.