ID of this snail?

[Aiptaisia anemone]

Anyone know the name of this snail? I found it at the galveston beach and ive had it for a month now, its a really good algae eater. I am planning on taking some more i wonder if its illegal?

 

[Aiptaisia anemone]

 

[Sticker shock]

Possibly an interrupted periwinkle. No idea what the collection rules are.