160 THE AMEBIC AN NATURALIST [Vol. XLIV 



by gentle tapping with his exceedingly long first leg pair. 

 In Prosthesima atra (Htz.) the male appropriates imma- 

 ture females; there is no courtship, beyond a tapping 

 with the legs. The two sexes of Geotrecha crocata 

 (Keys.) do not recognize each other by sight ; a mating 

 was observed, but no courtship preceded it. Also indi- 

 viduals of Geotrecha pinnata Kmert, do not recognize 

 one another by sight, perceiving each other only when 

 nearly in contact —so probably by air pressure (touch) ; 

 they run rapidly, and in the open on overcast after- 

 noons, so they might be expected to form visual images, 

 but they showed no signs of recognizing each other by 

 sight. After a mating the male always leaves the female 

 for a few moments, then returns to her again, and at 

 such times he moves in an irregular path, feeling for 

 her. He recognizes her by contact, and taps her legs 

 with his own until she becomes quiet. In one case a 

 female accepted in succession and repeatedly the em- 

 braces of two different males, one of which had only a 

 single palpus ; here the female exhibited no choice what- 

 soever. In the drassids, accordingly, sex recognition is 

 wholly by touch; the male sometimes seizes the female 

 by storm, sometimes subjugates her by tapping with 

 his legs. 



In the thomisids we have to do with diurnal spiders 

 that lie in wait for their prey, without constructing web 

 lines (except drop lines); they are mostly found upon 

 vegetation above the ground. The male is more nimble 

 than the female and smaller, sometimes much smaller. 

 In Micrommata virescens Menge (1874) saw the male 

 jump upon the back of the female. In Xysticus stom- 

 achosus Keys. I found (1903) that the sexes recognize 

 each other by sight to some extent, but that the male 

 pays no particular attention to the female until he 

 touches her, when he quickly seizes one of her fore feet 

 with one of his and nimbly swings around and mounts 

 her from the rear. Last summer I saw somewhat similar 

 behavior in X. nervosus Banks: the male seemed to 



