Can someone help me ID this snail?

[StianA]

Hello,
Im brand new to the saltwater world and need help with the ID of these snails.
I got 40 of them from a guy who cannot tell me the name of them. Just want to make sure im not putting something in my tank ill later regret. Also, I was wondering if snails can bring with them pests such as flatworms.

Thanks so much for your help!

 

[StianA]

 

[Sk8r]

It's not working. Try a free account with Photobucket, which will size and handle the URL source in a way this site understands.

 

[thegrun]

It's a Ghost Snail