black body, brown legs striped abdomen, Champaign, IL
Found speeding across the kitchen floor a couple nights ago (July 21). Amazingly fast. Like lightning fast. Almost impossible to catch fast. I've scoured hundreds of images on the web, but can't even get a clue. In one of the images you can see the sparse irregular webbing it created in the little plastic box I have it in. Body is about 5/16" long. Leg span front to back about 7/8".
Hey there curiousgeorge,
Cool spider you found. I believe you found a ground spider in the genus Castianeira, possibly a C. variata. These are ground hunters, that run around and catch prey. They often find their way into homes while on the hunt. Don't worry though, it's not dangerous to you or your pet (if you have any), and the best thing to do would be to just relocate it outside.
Excellent call, Whitlock!