Not sure what these are they just started growing in my sump

[jgaroppo]

So I noticed these multiplying in my sump about 2 weeks ago could anyone help identify and let me know if they are bad or good and if bad how to get rid of them and if good how to make them stop reproducing. The first two are the top that is hard the underneath is something like a snail.thank uou

 

[Reefer Reboot]

Research Jingle Shell to see if it matches.