228 AMERICAN SPIDERS 



which have separately arisen the crab and jumping spiders, have 

 become specialists in their own way. Whereas they must concede 

 superiority in daylight hunting to the jumping spiders and wolf 

 spiders, and to a few of the ambushing crab spiders, they have less 

 competition at night. Their distrust of sunlight has kept them essen- 

 tially night hunters or shy shade hunters under debris by day 

 and they have as chief competitors the phlegmatic crab spiders and 

 nocturnal wolf spiders. 



The eyes of the running spiders are for the most part set close 

 together in a small group near the front of the head, are of small 

 and essentially equal size, and are not placed strategically for sight- 

 hunting. They probably see moving objects, and may have fair 

 close-range vision, but sight does not appear to play much of a part 

 in their nocturnal foraging. By day they remain as far as possible 

 in the shade of litter; they run rapidly across sunny open spaces 

 until able to hide themselves, when they again resume a more de- 

 liberate pace. Their front legs searchingly test the terrain, and they 

 are uncertain of the character of objects even of the near presence 

 of a prospective mate until they actually touch them. However, 

 they move about with a seeming boldness that belies this, and they 

 can hold their own with long-sighted spiders when they come to 

 grips. 



Many running spiders make flattened, tubelike retreats (Plate 

 XXX) of white silk, in which they remain by day, and in which 

 they molt, mate, and deposit their eggs. The ground-loving types 

 place the eggs under stones or in dark recesses under debris. The 

 plant spiders bend leaves or fold blades of grass, then bind them 

 down with silk to provide cosy domiciles. The eggs, held in the 

 usual two sheets forming a lenticular sac, are guarded by the 

 mother; she often remains until the young are hatched and dis- 

 persed. Some ground forms cover the sacs with debris, or camou- 

 flage them in other ways, before leaving them to their fate. 



The vagrants described in this section constitute a closely 

 grouped assemblage of ten families, many of them far more closely 

 related than are families in other spider series. Several hundred 

 species occur within our borders, but passing mention can be made 

 of only a few. 



The vagabonds of the family Gnaphosidae are mostly ground 

 spiders of somber coloration with few contrasting markings; the 

 dull grays, browns, and blacks deriving from a covering of short 

 hairs that gives them a velvety appearance. More flattened than 

 their near relatives, the clubionids, they differ from the latter also 



