230 AMERICAN HYMENOPTERA. 



MYZINID^. 

 Plesia frontalis Cress. 



Male, Congress Jet., July (F. H. Snow) ; Bill William's Fork, 

 August (F. H. Snow). 



CHRYSIDID^. 

 Notozus marginatum Patt 



Oak Creek Canon, 6000 ft., August F. H. Snow. 



Holopyga horns Aar. 



Oak Creek Canon, 6000 ft., July (F: H. Snow). 



Tetrachrysis cseruleus Fabr. 



Oak Creek Canon, August, 1902 (F. H. Snow). 



Tetrachrysis lanta Cress. 



Oak Creek Canon, 6000 ft., August, 1902 (F. H. Snow). 



Tetrachrysis tripartita Aar. 



Oak Creek Canon, 6000 ft., August, 1902 (F. H. Snow). 



Parnopes westcottii Mel. and Brues. 



Bill William's Fork, Augu.st (F. H. Snow). 



EUMENID^. 

 Eumenes bollii Cress. 



Oak Creek Canon, 6000 ft., July (F. H. Snow). 



Ancistrocerus birenimaculatus Sauss. 



Female and male, Humphrey's Peak, at base, 9500 ft., August 

 (F. H. Snow). 



Ancistrocerus bnstamenti Sauss. 



Two females, S. Arizona, August, 1902 (F. H. Snow). 



One specimen (246) has the clypeus rather bidentate, and the 

 postscutellum with a transverse yellow band. In other respects it 

 agrees with the description of the species. In the other specimen 

 (247) the yellow is entirely absent from the postscutellum. 



Ancistrocerus tuberculiceps Sauss. 



Oak Creek Canon, 6000 ft., July and August (F. H. Snow). 



