BY ROWLAND E. TURNER. 91 



b. Pygidium constricted at the base of the truncation. 



fi 2 . Second abdominal segment with less than seven trans- 

 verse carinae. 

 a 3 . Pygidium widened to the apex. 



a 4 . Second abdominal segment with six carinae. 



nubilipennis Sm. 197 

 b 4 . Second abdominal segment with five carinse. 



frauenfeldianus Sauss. 198 

 b 3 . Pygidium scarcely, if at all, widened to the apex, 

 a*. Second abdominal segment with five carinae. 



irritans Sm. 183 

 b 4 . Second abdominal segment with three or four carinas 

 near the base, the apical area delicately trans- 

 versely striated. 

 a r >. Pygidium lanceolate. 



ft 6 . Pronotum with a faint median carina. 



tubtrculifrons Sm.186 

 b 6 . Pronotum without a carina. 



ft 7 . Head nearly rectangular, as long as broad. 



insidiator Sm. 182 

 b 7 . Head broader than long. 

 a 8 . Head nearly rectangular. basalis Sm. 185 



b 8 . Head considerably narrowed posteriorly. 



melleus Westw. 181 

 b r >. Pygidium elongate-ovate. 



a 6 . Fifth ventral segment longitudinally striated. 



flavofasciatus Sm. 177 

 b 6 . Fifth ventral segment of the abdomen rugose. 



Jlavopictus Sm. 176 

 b' 2 . Second abdominal segment with seven or more trans- 

 verse carinae. 

 a 3 . First abdominal segment with oblique striae. 



a 4 . Head not excavated on the front; black and yellow. 



andreanus 187 



b 4 . Head excavated on each side; wholly black. 



ci 5 . The carinae on the second abdominal segment 



straight. carbonarius Sm. 188 



b 5 . The carinse at the base of the second segment 



strongly arched. moechus 189 



b 3 . First abdominal segment without oblique striae. 

 ft 4 . Epipygium expanding into lobes at the apex. 



ft 5 . The epipygium pointed, the lobes not mem- 

 branous pseustes 191 



