22 2 Annals Entomological Society of America [Vol.1, 



of pedipalps with many spinules cephalo-mesad below (Plate XIV, fig. 17) ; tar.si 

 P densely scopulate below, with two sub-apical and two sub-basal spines (97%); 

 next joint with four sub-apical spines (the middle two often quite slender) and 

 two laterals on each side (83%) (Plate XIV, fig. 29 P), also setose. Legs tawny, 

 more or less olivaceous mesad; tarsi I and II unarmed, not setose, metatarsi I not 

 setose, but with two apical spines and two laterals near outer margin, one near 

 inner margin (88%), metatarsi II slightly setose, with three apical spines and 

 two laterals on each margin (79%) (variations froin the formulae here adopted 

 as tj'pical are mostly due to the addition of one or more spines, usually slender 

 ones not affecting the arrangement or presence of the spines of the typical sys- 

 tem) (Plate XIV, fig. 29 'I" and "II"); patellae III Avith a patch of distinct 

 spines, ten to fifteen, or inore, usually with two curved rows below and the 

 remainder scattered above, commonly not constant in number on opposite 

 sides of an individtial (Plate XIV, fig. 18) ; femora IV with a dense bunch of black 

 setae at the outer apical edge, but not spinose as in Eut3-chides versicolor; tarsi 

 IV commonly spined, but withotit constant formula, occasionally unarmed; 

 legs otherwise as in other species of Aptostichus. Tarsal claws with two or three 

 large inner basal teeth, more or less continuous with the basal end of the outer 

 row of small teeth (Plate II, figs. 25-28). I can see no real difference between 

 the anterior and posterior claws as to the teeth. 



The above description is based upon a series of twenty-five 

 individuals, ranging from lo to 21 mm. length, the percentages 

 Sfiven above, however, taken from tabulations made when but 

 twenty-one were at hand. My No. 102 is taken as the type 

 specimen, and deposited in the Entomological Museum of Stan- 

 ford University. It was taken on the Stanford Estate, near the 

 Universit}^ The rest of my material was taken in the foothills 

 in this vicinity, in the ravines of the mountains west (not abo\'e 

 400 feet elevation, however), at Oceanview, San Francisco Co., 

 and in the gullies of the pine forest on the Monterey Peninsula, 

 it being the only trapdoor spider I have yet found there. Also a 

 cast skin was taken from an abandoned burrow near Alum Rock, 

 east of San Jose. It is the least common trapdoor species about 

 Stanford, but abundant in its limited range near. Pacific Grove. 

 I have not yet secured a male. 



The range of variation in intensity of color is correlated with 

 the light relations of the environment and cannot be considered 

 as of specific value. I' have studied carefully the series before 

 me, and while considerable variation exists between various 

 extremes, selected with respect to certain ^'ariable characters 

 (such as color, eye relations, thoracic pit, labial spinules, sternal 

 impressions, etc.), I can find no definite set of differences con- 

 stant enough to warrant specific separation of any two types 

 amongst this material. Those situated in the open average much 

 lighter in color, while those from the shades of the forested ravines 

 are darkest in pigmentation. This species appears to be closer 

 to A. clathratus than to A. atomarius. 



