178 THE CANADIAN ENTOMOLOGIST. 



Males. 

 Flagellum denticulate beneath ; orbits yellow, except at summit 



behind luteoloides. 



Flagellum ordinary ; orbits yellow below i. 



1. Band on segment i interrupted ; flagellum submoniliform, fulvous 



beneath dentarice, sp. nov. 



Band on segment i continuous ; flagellum unusually dark^ piceous be- 

 neatli, the joints unusually cylindrical luteohan. 



Nomada Scop. 

 Females. 

 Head and thorax black, with ferruginous ornaments ; abdomen black, 

 with yellow ornaments ; interrupted line on segment i, lateral marks 



on 2-3, continuous fasci;\i on 4-5 vidua. 



Head and thorax red, sutures, depressed and concealed portions 

 black I . 



1. Scutel quite low, convex, hardly bilobed ; joint 4 shorter than 12; 



black colour of head and thorax rather preponderating over the red ; 

 a yellow spot on each side of segments 2-3, two spots on each side 



of 4, a band or two spots on 5 simplex. 



Scutel crested, bilobed 2. 



2. Joint 4 shorter than 12 5. 



Joint 4 as long as 12 3. 



3. Front coxce with short spines ; pygidium subacute ; yellow fascia on 



segment 5 opaque, finely rugose, rather sparsely, feebly punctured : 



scutel strongly crested denticuhita. 



Front coxae without spines ; pygidium broadly subtruncate 4. 



4. A spot on each side of segments 2-3, two subdiscal cuneate spots on 



4 ; band on 5 shining, coarsely punctured ; larger Cressonii. 



A spot on each side of segments z-^ ; smaller Sayi. 



5. A spot on each side of segments 2-3, and usually a band or two spots 



'^^ 5 ; pygidium broadly rounded, closely pubescent . . Illinoiensis. 

 A spot on each side of segments 2-5 ; the smallest species . . . parva. 



Males. 



Abdomen mainly reddish ; vein a before Vg 3 



Abdomen mainly black i. 



I. Segments 2-3 with a spot on each side, i usually with an interrupted 

 band, 4 with a band or two spots on each side, 5 with a discal band 



