786 BULLETIN UNITED STATES GEOLOGICAL SUEVEY. 



Fam. NYSSONIDJE. 



Gorytes montanus Cresson, 

 Found in small numbers west of Colorado Springs, August 13. 



Fam. BEMBECIDJ^. 

 Monedula faseiata Fab. 



Extremely abundant on the sandy banks of a small stream in South- 

 western Denver. August 5 and later. They had penetrated the ground 

 in a few places, giving the surface the appearance of having been riddled 

 with large shot. 



Fam. SFHEGID^. 



AmniopMla pruinosa Cresson. 



Common on the plains in and near Denver, August 5 and later. This 

 interesting species was most common in localities between the rankly 

 growing flowers and weeds. Having thus a ready means to hide, it was 

 rather difficult to detect. 



Ammophila macra Cresson. 



Not very common. Occurring in Clear Creek Caiion, and also in 

 Beaver Brook Gulch, August 6 and 7. It is fond of alighting upon the 

 flowers of golden-rod, and of embedding itself in the abundant pollen. 



Priononyx atrata St. Farg. 



Moderately common on flowers in the region of Colorado Springs, Au- 

 gust 13 and later. 



Priononyx tJiomce Fab. 



Found on the high grounds west of Denver, but not very common, 

 August 18. 



Pelopceus cementarius Dr. 



A few specimens seen, and one captured in the street of Colorado 

 City, August 17. I did not find any of the mud cells, but doubtless 

 they were at hand in some of the wooden sheds or houses near. Some 

 of them were nervously jerking themselves about on the surface of the 

 damp soil near the Fountain Creek, but I did not actually observe them 

 in the act of making the usual mud pellets. 



Fam. POMPILID.E. 



Pompilus cvtMops Cresson. 



Moderately common on the i)lains west of Colorado Springs, August 

 16. It struck me as remarkable that I did not find this common-looking 

 form in other localities. 



Pompilus formosus Say. 



Several specimens of this very large and conspicuous wasp were found 

 on the hillside west of Caiion City, and two others were flying actively 

 over and around the tall weeds and flowers in the mouth of the Grand 



