364 BULLI^TIN UNITED STATES GEOLOGICAL SUEVEY. [Yol.T. 



above as well as beneath, and the arcuated yellow line on the metatho- 

 rax is situated as in the female. The mandibles are black, the head is 

 more pubescent than in the female, and the marginal and third submar- 

 ginal cells are not quite so widely separated as in the female. 



There are three genera of Bembecidce with short palpi. They are : 



Bembbx. — Labrum twice as long as broad ; mandibles armed with a 

 tooth; maxillary palpi three- or four-jointed, the fourth joint variable in 

 size and sometimes obsolete ; the maxillse when folded concealed by the 

 labrum ; labial palpi represented by a free clavate joint ) no sinus be- 

 tween the marginal and third submarginal cells ; apex of the abdomen 

 entire. 



MiCROBEMBEX n. g. — Labrum twice as long as broad; mandibles 

 slender, unarmed; maxillary palpi four-jointed; the maxillse when 

 folded concealed by the labrum ; labial palpi obsolete ; a distinct sinus 

 between the marginal and third submarginal cells, second submarginal 

 cell much narrowed towards the marginal, its inner side straight; apex 

 of the abdomen notched in the female. 



In addition to the type, monodonta, two Cuban forms {argentifrons 

 Cress, and armata Cress.) belong to this genus. They appear to be 

 varieties of monodonta. 



Steniolia Say. — Labrum not twice as long as broad, the base 

 swollen, the apex broadly truncate; mandibles armed with a tooth; 

 maxillary ijalpi three-jointed ; the maxillae when folded extending be- 

 yond the mesothorax; labial palpi represented by a free cylindrical 

 joint as long as the first joint of the maxillary palpi and which may 

 consist of two joints united ; a distinct sinus between the marginal and 

 third submarginal cells, the second submarginal cell not narrowed 

 towards the marginal; apex of the abdomen entire in the female. 



In addition to the type, Steniolia longirostra {Bemhex longirostra Say), 

 this genus contains Steniolia obliqiia {Monedula obliqua Cress., Proc. Ent. 

 Soc. Phila. iv, p. 469). 



EUMBNID.E. 



32. EuMENES BOLLii Cress., (? . 



33. Odynerus vagus Sauss., ^ . 



34. Odynerus annulatus Say,<?. 



35. Pterochilus quinque-fasoiatus Say, i 9 . 



The male is similar to the female. Specimens occur-having the meso- 

 scutum marked with ferruginous. 



VESPID.3E. 



S.,(?. 



37. Polistes variatus Cress., <? 9 . 



36. Polistes aurifer Sauss., <?. 



