Nope, those two are definitely nerites! Trust me, I'm a mollusk expert, LOL. Geez, what a lovely credential to add to my resume.
The good news is that they won't reproduce, and are good for keeping algae at bay. Bad news is that they both have some bad shell erosion, which is pretty much permanent with nerites. Make sure to add some calcium either to your water, or to their diet to keep it from getting worse. The shrimp will probably appreciate it as well!