This little animal found itself on a rock about to be submerged while I was planting iris in a new location. I photographed it then rescued it. It does not look like the other millipedes I've seen around here (which look like worms with fringe...the legs) in that the body segments weren't "smooth" but looked like a string of beads with dividers: very dark brown and light chocolate alternating. After looking at the millipede and centipede sections of the Guide, I think it's a millipede of some kind, not a centipede, mostly on the basis of the antennae. There is a picture in one of my books that looks sort of like this, but it has no label other than "millipede."

This picture was taken at midday, so the shadows can be confusing; that's one reason I couldn't tell how many legs per segment. I'm linking another image which shows the shape of the posterior end better.