Nomenclature inverse centre?

[Workshopshed]

What is the correct name for a centre that rather than being pointed is hollow. This allows a thin or pointed piece of work to be located in it.

I recently used one to turn some very thin rod with the centre supporting the tailstock end of the rod.

[kneedeepinswarf]

This type of centre is known as a female centre. It is used by the horological and instrument making trades, when very small diameter shafts have to be turned.

[Workshopshed]

Thanks, that's just what I used it for.