Crab spiders are much like jumping spiders — they don’t build a permanent web, and instead go hunting for their prey. Crab spider have smaller eyes than jumpers (relatively), and the eyes appear to extend out of a “hood” on the head. Their first two pairs of legs are much longer than their last two, and they use these long legs to grab prey and draw it in.
Tmarus floridensis, which has no common name, is a well-camouflaged crab spider. They are able to extend their long forelegs out in front of them and, holding perfectly still, resemble a knot in a piece of wood.
This handsome adult male (big pedipalps = male) was about an inch long, and came out of his hiding place (where I was photographing him) to tell me exactly what he thought of my camera skills. Unfortunately, this made him even more photogenic. (Yes, I left him alone after getting, uh, five shots of his impressive threat display!)