Pardosa sp with egg sac - side view, Heeswijk, Netherlands

For years I've been seeing these spiders run around on the forest floor in great numbers, and with each step I seem to disturb a few of them. But they're small and fast, and easily go into hiding. I had a bit more luck for once when this wolf spider was sitting still at a fallen tree on a hot day.

Possibly Pardosa lugubris, but an expert suggested this can only be determined by investigating their genitalia, a step I skipped :)