APPENDIX. 837 



with about five yellow bands, interrupted, but not narrow- 

 ed in the middle. 



Inhabits Pennsylvania. 



% Orbits anteriorly obsoletely tinged with dull yellow- 

 ish; antennas, first joint beneath yellow; hi/postoma, la- 

 brum, and mandibles hlviOik; palpi whitish; thorax punc- 

 tured ; a line on the anterior edge, with a spot at tip on 

 the pleura, and a small, longitudinal, oval spot each side 

 above the inferior wings, yellow ; scutel with a transverse 

 yellow line ; metathorax at tip each side compressed and 

 yellow; wings hyaline, very slightly tinged with fuligin- 

 ous; nervures fuscous; feet yellowish; thighs black 

 from the base to near the knee, first pair on the anterior 

 side only the basal half black ; tergum with about five or 

 six yellow bands, which are rather wider on the back and 

 interrupted by a very narrow space ; excepting the first 

 band which is slightly undulated, slightly narrowed on 

 the back, and interrupted by a wider space ; the ultimate 

 bands narrowed each side and interrupted near a spot on 

 the lateral margin ; terminal segment with large, dense 

 punctures, as numerous on the disk as upon the sides ; anus 

 three-spined, of which the lateral ones are curved ; venter 

 each side with a triangular spot at the tip of each of the 

 dorsal bands excepting the first. 



Length nearly half an inch. 



I have not seen the female, the male is in the collection 

 of Mr. William W. Wood. 



AST AT A, Latr. 



A. unicolor. Deep black, immaculate; wings dusky at 

 tip. 

 Inhabits North-west Territory and Missouri. 



