If you are talking about the snail on the left center part of the 2nd pic, that look like an astrea to me. The first pic looks like the foot of an astrea too. If you are talking about the thing on the right center part of the 2nd pic (cone shaped), that looks like a cerith snail to me. I think that may be a hermit in a cerith snail though.

The only snails I have had much success in breeding in captivity are stomatella and nerite snails.