look at this site, it identifies everything you want

[lottie_pufferfish]

i found this while googling "star snails"
http://home2.pacific.net.ph/%7Esweetyummy42/

Its great!

[Chad Vossen]

i have one of those star snails. i got it with a group of 10 astrea snails i bought from the group order. it and one other snail survived though. i think its just an astrea that was under different conditions and grew a different shell. idk though. its my favorite snail.
http://home2.pacific.net.ph/%7Esweetyummy42/snail1.jpg

[Adam G]

Nice link. I haven't found that one yet.

[steve1600cc]

Cool,I needed that!!