Synema parvula.—A common species in the South. Length about one-eighth of an inch. The thorax is as wide as long, round and high in the middle. The abdomen is as wide as long, widest across the middle, and a little pointed behind. The third and fourth legs are not more than two-thirds as long as the first and second, and lighter colored. The thorax is orange-colored, a little darker at the sides, and with a dark brown line on the edges over the legs. There are light rings around the eyes. The abdomen is white or light yellow in front, and has a wide black or brown band across the hinder half, not reaching back to the spinnerets, and sometimes partly divided by a notch in front. On the front half of the abdomen are some small dark spots and usually several opaque white marks. On the under side of the abdomen there is a dark band on each side extending back to and partly surrounding the spinnerets. The front legs are orange brown, with the femora darker on the front and rear edges. The other joints are a little darker at the ends. The males are a little smaller and darker in color, but differ little from the females.
THE GENUS XYSTICUS
In these spiders the general appearance is crab-like. The abdomen is not much larger than the thorax, and both are flat and wide. The first and second legs are a third longer than the third and fourth. The colors are usually various shades of brown and gray, in small spots and bands. On the upper side of each leg is usually a light line, with dark lines on each side of it. The gait is often sidewise, the legs kept close to the ground, so that the spider can move in a narrow crack. They live under stones and bark and leaves, and some, like triguttatus, on low plants. The males have longer legs and smaller abdomen and all the dark markings larger and darker than the females. In triguttatus there is great difference between the sexes, but in most species very little, as in limbatus and stomachosus. The head is generally low, and the four middle eyes form a rectangle a little wider than high [(fig. 97)].
Xysticus stomachosus.—A middle-sized and light-colored species, with gray markings on a light ground, the markings most distinct on the hinder legs and abdomen. The middle of the thorax is lighter than the sides, and there is a small dark spot in the middle and a larger one on each side toward the hinder end (figs. [87, 88]). The third and fourth legs have a distinct dark spot at the ends of femur, patella, and tibia. The abdomen is light, with a few small spots at the front end and three pairs of dark transverse bands on the hinder half. The hairs are short and fine. The male has longer legs and is marked in the same way, with the spots on the abdomen larger and extended farther forward.