THE CANADIAN ENTOMOLOGIST. 163 



Family XV^I. — Crabronid^. 

 The much larger head, which is quadrate or trapezoidal, with very 

 broad temples, the normally-shaped scutellums and the venation of the 

 front wings — the first and second discoidal cells always being distinctly 

 separated, never confluent — readily distinguish the family from the 

 Oxybelidie ; while from the Pemphredonidc-e, the only other family to 

 which it shows any affinity, it is at once separated by the venation of the 

 front wings and the intich longer median cell in the hind wings. 



In my studies on the genera of this family as well as many of the 

 other families, I am greatly indebted to my friend, Mr. \Vm. J. Fox, of 

 the Philadelphia Academy of Sciences, who most generously placed at 

 my disposal such of his types and other material needed. 



In this family I have recognized five distinct groups, which I call 

 subfamilies, although they are much closer related than some of the 

 subfamilies in other families. These may be distinguishable by the aid 

 of the following table : 



Table of Subfamilies. 

 .Abdomen beneath not flat, either convex or subconvex and laterally 

 rounded, not acute or carinate, the dorsal segments usually normal, 

 rarely distinctly constricted at the sutures ; second discoidal cell not 



much longer than the first, often shorter and not very narrow 2. 



Abdomen sessile, beneath very flat, and laterally acute or carinate, the 



dorsal segments with a constriction at the sutures and margined at 



apex ] transverse median nervure in front wings uniting with the 



median vein far before the origin of the basal nervure, the second 



discoidal cell, in consequence, being very long and narrow, much 



longer than the first discoidal cell ; first recurrent nervure joining the 



first cubital cell at or near the middle; mesopleura sharply margined 



anteriorly and posteriorly, and the carina of same connected with a 



carina along the sides of the mesosternum ; mandibles at apex edentate 



acute; maxillary palpi 6-, labial 4-jointed. .Subfamily I., Anacrabroninae. 



2. Mandibles at apex simple, edentate ; maxillary palpi 6-, labial palpi 



4-jointed ; first recurrent nervure received by the first cubital 



cell at or near the middle, never very far beyond the 



middle Subfamily II., l^indeniinse. 



Mandibles at apex 2- or 3dentate, rarely truncate and indistinctly 

 bidentate in a few females; never, however, acute, as in the Anacro- 

 broninc^ and the Lindeniince. 



