Drassus saccatus.—Four-fifths of an inch long, and pale, without markings. The head is shorter and wider than in Gnaphosa conspersa and Prosthesima atra, and the eyes cover a larger part of the head. Both rows of eyes (figs. [2], [19]) are curved, with the middle highest. The middle upper pair are oval and turned apart toward the front. The lateral eyes are twice their diameter from the middle pair. The maxillæ [(fig. 1)] are widened at the ends on both sides. The labium is as wide as it is long, narrowed toward the end but truncated at the tip. The color is light gray, with short fine hairs all over the body. The front of the head, the feet, and the mandibles and maxillæ are darker and browner. The abdomen is marked only with the usual four muscular spots and sometimes a few transverse dark markings toward the hinder end. The legs are long and tapering in both sexes. The male is smaller and more slender than the female, and the male palpi are long, with the end very little enlarged. They live under stones, and make a large transparent bag of silk in which the female makes her cocoon of eggs, and stays with it until the young come out. Early in the summer a male and female often live together in the nest, even before the female is mature.
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.
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.