Small flint?

[blenberry]

No: HPFGUIDX 33164

First of all, I have American copies of all the books (unfortunately).

In CoS, Moaning Myrtle dives into the toilet and comes to 
rest "somewhere in the U-bend" (p 157).

When we encounter her again in GoF, she is described as "usually to 
be heard sobbing in the S-bend of a toilet three floors below" (p 
461).

I don't know too much about plumbing, so which do toilets have?  I'm 
familiar with the U-bend or trap under sinks, but I looked behind my 
(American) toilet and couldn't find it.

blenberry