Name that butterfly!

Recently I have seen some very beautiful butterflies around CSIRO so I thought I go and see if I could spot some in the gardens.  There are plenty of LBBs (little brown butterflies!) around - particularly this 'Common Brown' one, Heteronympha merope.  The first picture is the female, the second the male, interesting that the female is more striking than the male, in nature it generally tends to be the other way round!

I aslo saw this butterfly, it is a white butterfly but appeared greenish when closing its wings against the light.  It behaved in a very interesting way, moving quickly then hovering like a hummingbird next to the flowers rather than landing on them to get the nectar.  I can't identify it from a quick scan of the web, any ideas anyone?!