difference between cypraea zebra and cervinetta

[shellhunk]

Hi! I am happy I found this site. I've been collecting shells for a few years now and I am trying to catalogue my shells. I am no expert but I'm learning fast through research and passionate collecting. I have lots of questions especially in identifying the shells and I will appreciate any help. Please <img src="images/smiley/smile.gif" alt="" border="0" />
What is the difference between a cyprae zebra and a cervinetta? I have three big ones they all look similar.
How about a cypraea leviathan from just a cypraea carneola. I have several huge "carneolas" (60-70+mm) and I'm thinking they are leviathans because I find only small carneolas on the internet.
These two for now.
Chris