Some garden arthropods

Lately we've been finding some interesting creatures of the vertebra-less variety in various parts of the garden:

Some type of flat millipede I found walking across the lawn

A rare black purse-weaver (Sphodros niger)

I've had difficulty identifying this very large beetle. My best guesses are that it's some sort of long horn or blister beetle. If you know what it is, let me know!