274 HYMENOPTERA OF AMERICA. [PART I. 



Metathorax vertically truncate ; concave, but its margins not 

 ridged, the edges being quite blunted by the dense punctuation. 

 Abdomen subcorneal, rather slender. The first segment smooth 

 and silky ; the second very short, densely punctate everywhere, 

 but its posterior margin having a broad excavated band of very 

 coarse punctures ; segments 3-4 very coarsely punctured. 



Black; mandibles, clypeus, scape of the antennae, a frontal 

 mark, and a large spot behind the eyes, rufous. Clypeus' often 

 with a transverse black line or with three black spots in a trans- 

 verse line. Anterior margin of prothorax broadly, the posterior 

 narrowly rufous, or partly sulphur-yellow ; tegulae yellow and 

 rufous, often a yellow spot under the w r ing ; post-scutel yellow ; 

 lateral margins of metathorax rufous or yellow. Abdomen having 

 its first four segments margined with yellow ; this color often pre- 

 ceded by a little of rufous. First segment black in middle ; its 

 sides rufous, with a yellow spot fused with the yellow band. 

 Second segment often adorned with two separate rufous spots. 

 Legs ferruginous ; coxae blackish. YTings grayish ferruginous, 

 a little clouded or sometimes even with violet iridescence. 



Rufous Variety. — Head rufous, except the vertex. Prothorax 

 and feet rufous. Scutels yellow, or rufous, tinged with yellow ; 

 mesothorax black, with a rufous spot; metathorax rufous, marked 

 with yellow. First and second abdominal segments rufous, 

 margined with yellow; the second with two yellow maculae; 3-5 

 segments rufous, margined with yellow; 6th rufous. Wings 

 clouded (Kansas, New Mexico). 



Various Varieties. — This is quite a variable species, the three 

 colors interchanging, which gives numerous combinations. The 

 scape is more or less obscure above. The spots on the clypeus, 

 under the wing, on the second segment, are often wanting, etc. 

 The yellow ornaments are of a pale sulphur-yellow. 



I consider, as the male of this species, specimens from Texas 

 and Louisiana, which last constitutes a still more rufous variety. 



%. Head large, wider than high, rufous, with black vertex. 

 Clypeus broader than high, regularly octagonal ; its anterior 

 margin straight, having two insensible, distant teeth at its 

 extremity. Mandibles, clypeus, a triangle on the forehead and 

 sinus of the eyes, a line on the scape, bright yellow; hook of 



