crystal structure - R32 Space Group (Crystallography)

Why R32 Space Group is so named? I mean, if R stands for Rhombohedral and 3 for Threefold Axis, what 2 stands for?

I don't see any Twofold Axis in the cell:

http://img.chem.ucl.ac.uk/sgp/large/155az1.htm

EDIT:

What does it means 1/2, 2/3 and 1/6 on the arrows?

R32 have two cells.

This one: http://img.chem.ucl.ac.uk/sgp/large/155bz1.htm

And this other: http://img.chem.ucl.ac.uk/sgp/large/155az1.htm

Are they equivalent?

EDIT:

I have traced some lines to mark the screw-axes and the twofold-axis, but i can't see any point that follow the simmetry operator and the element of simmetry. Maybe i don't understand how it works.

Which is the height of the green line? And, which are the points of the screw-axis of the yellow line?