chamberlin: new spiders of the family aviculariidae. 75 



1.8 times longer than the patella. Tarsus short, subhemispherical. 

 Bulb of palpal organ subglobular or somewhat pyriform; spine stout, 

 strongly curved, bifid toward end, showing on the mesal side a distally 

 broadly rounded division with edge and surface finely denticulate or 

 tuberculated, and on the ectal side an acutely pointed longer process. 



Male (type). Length, 13 mm. 



Cephalothorax : length, 6.4 mm.; width, 5.3 mm. 



Readily distinguished from B. pacificuin Simon, also described from 

 Washington, in having a dense patch of spines on both inner and outer 

 surface of tibia I of male instead of only on the inner (anterior) surface, 

 as well as in presenting pronounced differences in the palpal organ. 

 From B. robustum Simon, which it seems most to resemble, it differs, 

 among other points, in the palpal organ and in the modifications of 

 leg I. 



