62 



Illinois Natural History Survey Bulletin 



Vol. 23, Art. 1 



18. Lateral lobes o\ eighth sternite long 



and narrow, figs. 251, 253 19 



Lateral lobes of eighth sternite shorter 

 and wider, almost quadrate, figs. 

 260, 261 27 



19. Base of eighth sternite with a definite 



shelf or ledge with a sharp edge, 

 situated between lateral lobes, figs. 

 251, 252 20 



Base of eighth sternite without a ledge 

 situated between lateral lobes, figs. 

 253-259 21 



20. Eighth sternite with basal ledge nar- 

 row; lateral lobes long, slightly ex- 

 panded near apex and with an angu- 

 late foot, fig. 251. . . interruptus, p. 69 

 Eighth sternite with basal ledge wide; 

 lateral lobes therefore farther apart. 



248 C 



n k ^^j*' 2*5-248.— Po/yf^«/ro^«j, male genitalia. A, lateral aspect; 5, ventral aspect: 

 C, baso dorsal appendage of clasper; D, aedeagus. 



