BY ROWLAND E. TURNER. 73 



b 9 . Hypopygium sharply narrowed near the 

 base, narrowly truncate at the apex. 



proximus 8 



b 8 . Abdomen wholly black. nitidulus 10 



c 7 . Hypopygium triangular. 



a 5 . Abdomen black politus 14 



b 8 . Abdomen light ferruginous-red. cryptoides Sm. 11 

 b±. The second cubital cell as long or longer than the 

 third on the radial nervure. 

 a 5 . Posterior femora with a large tubercle beneath. 



a 6 . Abdomen black. calcaratus Sm. 15 



b 6 . Second and third segments of the abdomen 



dark ferruginous femoratus 16 



b 5 . Posterior femora without a tubercle; the abdomen 



ferruginous. volatilis Sm. 17 



b 3 . The three apical joints of the maxillary palpi not 

 elongate. 

 a 4 . Hypopygium strongly emarginate. xanthorrhoei Sm. 20 



?>*. Hypopygium not emarginate, blunt at the apex. 

 a 5 . Clypeus strongly convex, truncate at the apex. 

 a 6 . Hypopygium with a spine on each side near 



the base. sitiens 26 



ft 6 . Hypopygium entirely without spines. 

 a 1 . Abdomen black and yellow. 



a 8 . Abdomen black with yellow spots on the 



sides. contiguus 21 



b 8 . Abdomen black with yellow bands or 

 lunules 

 a 9 . The yellow bands on the abdomen broad. 

 a 10 . The yellow bands interrupted in the 



middle. trifidus Westw. 23 



b 10 . Tho yellow bands not interrupted. 



flavescens Sm. 25 

 b 9 . The bands on the abdomen narrow and 



lunulate carinatus Sm. 24 



b 1 . Abdomen black and ferruginous, sedulus Sm. 27 



b s . Clypeus not very strongly convex and slightly 



emarginate marginalisWestw. 22 



}>* The abdomen not much flattened, the segments often 

 constricted. 

 a 8 . The first dorsal segment of the abdomen without a 

 tubercle at the base. 

 a 4 . The hypopygium not triangular or subtriangular, 

 8 



