Slide 31:

There are two major groups of arthropods. The chelicerates have their mouthparts in the form of pincers, called chelicerae. Here, the chelicerae are large, including all of the head in front of the eyes.

This is a sun spider photographed in Arizona. A similar species is found very rarely in southern Saskatchewan. All of the chelicerates have four pairs of legs. The pair of leg-like appendages on either side of the sun spider's head are accessory mouthparts called pedipalps.