Tibellus duttonii.—This is a very common spider on bushes and grass. The body is slender, from a third to half an inch long, and a tenth of an inch wide [(fig. 115)]. The thorax is an eighth of an inch long, widest across the hinder half and narrowed toward the front, where it is cut off nearly straight over the mandibles. Both rows of eyes are strongly curved [(fig. 116)]. The hinder row is twice as long as the front row and all the eyes larger. The abdomen is straight at the sides and a little pointed behind. The color is light gray or yellow, with a darker gray line in the middle, divided into two toward the eyes. At the sides of the thorax are other longitudinal lines. On the abdomen, one-third its length from the hinder end, is a pair of small round or oval black spots. The legs are light gray, with no markings except a few black hairs.

Thanatus coloradensis or lycosoides.—In color and general appearance this resembles Philodromus, but is not as flat, and the legs are not as long and slender. The general color is light gray, with a distinct wide light stripe in the middle of the thorax, and a dark brown pointed stripe with white edges in the middle of the front half of the abdomen [(fig. 117)]. The head is a little longer and higher than in most Thomisidæ, and the abdomen is a little longer and not so much widened behind. The eyes are much as in Philodromus, but larger and nearer together. The whole body is hairy, with longer and darker hairs scattered among the short ones. The males differ but little from the females except in having a little longer hairs and darker color. They live on plants and may be mistaken for Philodromus (p. [35]) or for Ocyale undata (p. [88]).

THE ATTIDÆ

The Attidæ are jumping spiders, many of them brightly colored and quick in their movements and living in open places among the tops of low plants. They are usually short and stout spiders, with a large cephalothorax, which is wide in front, where the eyes have a peculiar arrangement in three rows [(fig. 118)], somewhat as in the Lycosidæ, but with the middle eyes of the front row much the largest, so that at first sight many of them appear to have only two eyes. The eyes of the second row are very small and hard to see, and those of the third row are far back on the head and usually turned a little backward. The front legs are usually thicker than the others, especially in the males. The relative length of the legs is variable, the first pair being commonly the longest, but sometimes the fourth and even in some species the third pair. The feet have two claws, with many fine teeth and a thick brush of hairs. The Attidæ are usually thickly covered with hair or scales, often brightly colored or iridescent, and their appearance is often entirely changed by rubbing or wetting.