right, it was the description also, that it separates. the flesh is the snails mantle that comes out and keeps the shell clean. you see these snail shells sold in all the shell shops by the hundreds.
I forgot to mention that it is rare to see them during the day, I only see mine at night.
That is most likely to be a money corie. They top off at about 1.5" very cool animal. You can some times buy them for about $6. They are algae grazers. fairly delicate, if you have emerald crab, it may eat the corie.
Some of the larger cories such at the tiger corie will eat soft corals, but yours I believe is reef safe.