Flat Jumping Spider (Holoplatys lhotskyi)

About 6 mm long, this very flat spider emerged out of the slit in between wooden wall panels. The cephalothorax was black with distinct white lateral lines. Body was covered with short brown setae. The front pair of legs were thick and held out. Each of the last two pairs showed a white streak. The incredible flatness can be seen in pic 2, just beside the slit between the panels.
This spider lives and hunts in cracks in tree bark and wood in buildings.