Altocumulus Waves, June 30th

We're having a few decent sunsets this year, slightly making up for the lack of any other interesting weather! The colours first drew my eye on the 30th. Note the hint of mammatus at the top of the photo in the cirrus:

With perfect timing, a patch of Altocumulus moved across from the west. As it did so, it developed a series of pronounced waves in shapes I've not seen before:

As the light was fading, the area of waves moved overhead. By this time they had become very thin and looked like a set of thin fingers hanging in the air: