Original description on Flickr:

This is an egg-case of A. australiensis, a terrestrial nemertine, or proboscis worm. You can see one in the foreground, wriggling away, obviously a little smaller than they can be! Fully grown they can be around 40mm long. This nemertine is the most common of Tasmanian species with an egg-case measuring around 10mm long. These 'worms' are able to shoot out a white proboscis in the pursuit and eventual cold blooded murder of springtails and other prey. Which I don't approve of, obviously.

This is a 37 photo stack, the first time ever when apart from sorting out the moving worm in the foreground, I didn't have to touch up the finished stack at all! Which as all of us who do this kind of photography will know, is unusual, even in static shots...