14 Myron Harmon Sicenk 



both sexes distinctly though sometimes but slightly 

 shorter than 4, rarely as long as or longer than 4. 



Head and thorax of female without yellow ornaments, 

 except that sometimes there are small yellow spots on 

 the lower corners of the face, but red with the sutures, 

 depressed and concealed portions black, the basal abdom- 

 inal tergites often with usually interrupted bands, 

 these often reduced to lateral spots or the abdomen is 

 entirely immaculate; male usually without entire and 

 continuous yellow bands on tergites 1-6 but often with 

 lateral spots, or if with continuous bands these are 

 usually more or less emarginate at extreme sides pos- 

 teriorly and that on 5 has lateral spots nearly or quite 



cut off by the emarginations Xomada 



(Type Nouiada riificoniis L.) 



Head and thorax of female almost always with yellow 

 ornaments, these very rarely lacking, usually on a 

 black ground color, the abdominal tergites with mostly 

 continuous yellow bands but these sometimes inter- 

 rupted on tergites 1-3 ; male with entire and continu- 

 . ous yellow bands on abdominal tergites 1-6 except that 



the band on i is sometimes interrupted or lacking, the 

 band on tergite 5 without isolated or nearly isolated 



lateral spots Heminomada 



(Type Nomada obliterafa Cresson) 



Apex of male rounded and entire ; antennal joint 3 of the 



female usually longer than or at least equal to 4, rarely 



a little shorter, sometimes subequal to or shorter than 



4 in the male (Phor spp.)- 



Head and thorax of female almost always with yellow 

 ornaments, and almost always of a black ground color, 

 rarely red (e. g., asteris) ; antennal joint 3 of male 

 exceeding 4; abdominal maculations yellow, usually 

 forming continuous bands, rarely cream color. 



Holonomada 

 (Type Nomada snperha Cresson) 



Head and thorax of female without yellow ornaments 

 but red with the sutures, depressed and concealed por- 

 tions black; antennal joint 3 of male shorter than 4; 

 abdominal maculations whitish, forming widely inter- 

 rupted bands or lateral spots Phor^ 



(Type Nomada integerrima D. T.) 



'Although not included in the Nebraska fauna the subgenus Phor is 

 included in the above table for the sake of completeness. 



14 



