Need help to identify Costa rica Pacific shell....beginner issue

[paul monfils]

Hi,

398/400 is Chione subrugosa

451/452 are either Cypraea arabicula and/or Cypraea robertsi, difficult to separate when they are this beachworn.  I could go out on a limb and say that the apparently more narrow shell with the darker ground color, on the left is more likely C. arabicula, and the broader shell with the lighter ground color is more probably C. robertsi.  You will probably find better specimens, since both of these are common in your area.

456/457 is a Cerithium, best guess Cerithium gallapaginis, not sure

458/459 is Planaxis planicostata

Keens lists both the Trivias as "moderately common", but I believe T. solandri is more common than T. radians.

If you have additional shells to post, please start a new thread, so this one doesn't become too long.

Paul M.