146 Proceedings of the Biological Society of Washington. 



KEY TO THE GENERA OF NORTH AMERICAN GNAPHOSIDAE. 



a. Lower margin of the furrow of chelicera keeled or lobed. 



b. Lowertinargin of furrow with three contiguous, chitinous lobes. 



Laronia Simon, 

 bb. Lower|margin of furrow with a single keel. 



c. Posterior row of eyes much longer than the anterior, strongly 

 recurved, with the median eyes usually obviously nearer to 



each other than to the laterals Gnaphosa Latreille. 



cc. Posterior row of eyes but little longer than the anterior, the 

 eyes equidistant or the medians farther from each other 



than from the laterals Callilepis Westring. 



aa. Lower margin of furrow of chelicera unarmed or with from one to 

 three ordinary teeth. 

 b. Posterior row of eyes very strongly procurved, semicircular or 

 nearly so. 

 c. Lower margin of furrow of chelicera unarmed; bulb of pal- 

 pus of male simple, with no true apophysis. 



Megamyrmecion Reuss. 

 cc. Lower margin of furrow of chelicera with one tooth; bulb of 

 palpus of male with a stout median apophysis 



Scopodes, gen. nov. 

 bb. Posterior row of eyes not thus strongly procurved. 



c. Tibia IV with two, or less commonly with three or five, median 

 dorsal spines. III with one or two. 

 d. Lower margin of furrow of chelicera with two or three 

 teeth, 

 e. Eye rows close together, the laterals on each side 

 separated by a distance decidedly less than their 

 diameter, usually only equalling or less than their 

 radius; posterior median eyes well separated, being 

 only a little farther from the laterals than from each 

 other, 

 f. Lower margin of furrow of chelicera with three 

 teeth, the upper with five..... Sosticus, gen. nov. 

 ff. Lower margin of furrow of chelicera with two 

 teeth, the upper with three. 



Rachodrassus, gen. nov. 

 ee. Eye rows widely separated, the laterals on each side 

 separated by a distance about equalling or else 

 exceeding their diameter; posterior median eyes 

 much nearer to each other than to the laterals. 

 (Tibia of palpus of male much longer than the 

 tarsus; bulb with a single small apophysis ectad 



of base of embolus). Drassodes Westring. 



dd. Lower margin of furrow of chelicera with a single tooth. 



Geodrassus, gen. nov. 

 cc. Tibia IV with a single median dorsal spine or with none. 



