What is the Name of this Unknown Molecule?

[Bohrok]

I've studied a little organic chemistry but I couldn't figure it out. I've never seen it before but I'm sure it's simple to name, yet I couldn't find anything on Google.

 

[zhermes]

poly-cyclic carbon molecules linked by a single carbon are colled "Spiro" molecules, they're named as a single chain with the 'spiro' prefix, and the number of carbons in each ring in brackets (besides the linking carbon, which is called the 'spirocarbon').

The molecule above is therefore called spiro[4.4]nonane

Edit: http://en.wikipedia.org/wiki/Spiro_compound this explains it.

 

[Bohrok]

Thank you very much, that was bugging me for some time.