Hitchhiker ID

[CaptainK]

Hi All,
I cannot believe that after all this time having my tank I missed seeing this crab. What else do I have in there!
Well it is a crab and has a somewhat whitish colored body. The legs look banded with white and black stripes. Its claws are black and it is almost the size of a nickel.
Anyone seen these before or have a name for it?
It almost looks like a green emerald, but without the green. If I ever see it again I will try to get a picture.

Thanks,
CaptK

[Mikeman]

Could it be a sallylightfoot crab?