ID snail, possible pyramid snail

[Euphoric Eulogy]

A few days ago I bought a second hand aquarium and I noticed these little snails that come out late at night out of the sand. They don't seem like collonista snails because these guys are cone shaped. They vary in shades of brown to white. My initial thought were pyramid snails but before I discovered that I had these snails, I went and bought some astrea and margarita snails and they don't seem to be on them.

Please let me know what you think they could be.

 

[GerritM]

That´s Nassarius sp. They don´t grow much bigger.

 

[Euphoric Eulogy]

That's what I was thinking but I thought nassarius were larger. These guys are smaller about the size of a grain of rice.