$Geotrecha crocata.$--Black, with the ends of the legs light yellow and a bright red spot on the end of the abdomen. It is about a third of an inch long. The legs are slender and the body is not at all flattened. The cephalothorax is two-thirds as wide as long, oval behind and narrowed in front of the legs, where the sides of the head are nearly parallel. The abdomen is oval and nearly twice as long as wide. The spinnerets are so far under the body that they show but little from above. At the front end of the abdomen is a spot larger below than above, where the skin is thicker and harder and browner in color than the rest. The cephalothorax is dark brown or black, as are also the femora of all the legs and of the palpi. The ends of the third and fourth legs are a lighter brown and the ends of the first and second legs and palpi light yellow. The abdomen is deep black except a bright red spot at the hinder end, which varies in size, is sometimes broken into several spots, or is sometimes wanting altogether. The eyes (fig. 20) are near together, the upper row curved down at the ends. The maxillæ are straight, with the sides nearly parallel, and the labium is shorter than wide. The males are usually smaller than the females and have the red spot larger. These spiders live among stones in dry open places. They are easily alarmed and move very rapidly. The flat, parchment-like cocoons found on stones are probably made by this species. [Illustration: FIG. 23. FIG. 24. Geotrecha bivittata.--Upper and under views of female enlarged four times.] $Geotrecha bivittata.$--The same size as _G. crocata_ but much lighter colored, and with two white stripes across the abdomen (fig. 23). The cephalothorax is a little narrower behind than it is in _crocata_. Its color varies from orange to dark brown. The femora of all the legs are striped lengthwise with brown and yellow. The hind legs are brown, with a little yellow on the upper side of the patella and tibia. The other legs are yellow, sometimes with brown stripes on the under side. The white marks on the abdomen extend underneath halfway to the middle line. The sternum and under side are light brown. It lives under leaves at all seasons. [Illustration: FIGS. 25, 26, 27, 28. Micaria longipes.--28, Male enlarged four times. 25, eyes seen from in front. 26, maxillæ, labium, and ends of mandibles from below. 27, Southern variety, Micaria aurata. Colored orange, with black and white markings.]