Habrocestum auratum.—In life this spider is covered with bluish white hairs that give it a light gray color and obscure the markings. The markings of the male are so much stronger that those of both sexes can be best understood by describing the male first [(fig. 122)]. The cephalothorax has a white middle stripe for a short distance back from the front eyes and two distinct white stripes from the lateral front eyes back the whole length. In the middle of the head are two small white spots and just behind them between the posterior eyes two curved white lines. The latter marks show indistinctly in the females. Down at the sides of the cephalothorax are white stripes meeting in front under the eyes. The abdomen has a white line extending entirely around it and a middle stripe of varying width.
The female [(fig. 123)] has only faint indications of the markings of the cephalothorax, usually a little lighter color in the middle and at the sides below the eyes. The white stripe around the abdomen is broken into three pairs of oblique white markings and the middle stripe into several spots or pairs of spots. There is nothing distinctive in the markings of the under side or of the legs except the ornaments of the male.
The front legs of the male [(fig. 125)] in this species are much ornamented. The femur has long black hairs on the under side. The patella has long black hairs beneath, a spot of short black hairs on the inner side, and a crest of long white hairs mixed with shorter black on the upper side. The tibia is covered with long black hairs except at the tip, where they are white. There is nothing peculiar about the third leg [(fig. 124)]. The form and general appearance can best be understood from the figures.
At the mating time the males, as they approach the females, hold the front legs extended sidewise and lifted a little from the ground, with the tibia nearly horizontal and the tarsus turned downward. In this position they advance slowly, at the same time running rapidly sidewise from one side to the other and at short intervals jerking the abdomen and the front legs slightly upward. They go almost close enough to touch the female and then quickly retreat.
Habrocestum peregrinum.—This is about the same size as auratum and looks very much like it. The female, at any rate in alcohol, has a more distinct light mark in the middle of the cephalothorax, curving under the eyes and pointing forward in the middle [(fig. 128)]. The abdomen has light markings in the middle similar to those of auratum, but those at the sides are less distinct.