108 R. W. Dawson 



13. Fixed spur of hind tibiae cylindrical and curved inwardly to the 

 middle where it is suddenly flattened and sharply bent out- 

 wardly, the terminal portion being straight and tapering to 



the tip futilis 



Fixed spur of hind tibiae not sharply bent at the middle 14 



14. Fixed spur of hind tibiae long, nearly parallel-sided, strongly, 

 and roundly bent or bluntly hooked at the tip vehemens 



Fixed spur of hind tibiae not strongly and roundly hooked at 

 the tip 15 



15. Genital armature symmetrical, the claspers alike in size and 

 shape 25 



Genital armature not symmetrical although sometimes nearly 



so 16 



16. Genital armature viewed from the end showing principally the 

 elevated edges of the chitinous plates 17 



Genital armature viewed from the end showing principally 

 broadened surfaces, the edges of the plates directed inwardly 

 instead of being elevated 21 



17. Under surface of abdomen with a longitudinal, sharply im- 

 pressed line which divides the transverse ridge on the fifth 

 abdominal sternite bipartita 



Under surface of abdomen without a sharply impressed longi- 

 tudinal line 18 



18. Genital armature usually large, the terminal portion expanded, 

 distinctly wider than the stalk of the armature 19 



Genital armature much smaller, the terminal portion not ex- 

 panded and scarcely, if any, wider than the narrowest portion 

 of the stalk 20 



19. Hind tibial spurs large, very broad and flat, the widest portion 

 of the movable spur distinctly wider than the basal third of the 

 first tarsal joint horni 



Hind tibial spurs of average size and width, widest part of the 

 movable spur not wider than the basal third of the first tarsal 

 joint rugosa 



20. Pronotum very coarsely pitted, spurs of hind tibiae nearly 

 equal in length corrosa 



214 



