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PROCEEDINGS OF THE NATIONAL MUSEUM 



tennae with the terminal segment strongly hooked, ferruginous 

 basally, and fuscous apically with a trace of yellow on the scape. 



Thorax black except for two patches on the pronotum, the meta- 

 notum, and the tegulae, all of which are yellow; tegulae low and 

 smooth; enclosure smooth except for a medial groove and pits in the 

 lateral angles; mesosternal tubercles absent; legs fulvous; wings 

 subhy aline shaded with brown. 



Abdomen with tergum 1 black to fulvous ; terga 2 to 6 with yellow 

 bands variable in width and emargination, the emarginations more or 

 less bordered with fulvous; venter dark, more or less marked with 

 fulvous; pygidium narrowing apically and ending in a broad medial 

 extension flanked by lateral acute denticles. 



Both sexes show color pattern variation but these are more con- 

 spicuous in the females and are related geographically. The first 

 tergum of the male varies from black to fulvous. The abdomen of the 

 female in the nominate subspecies has the yellow confined to the large 

 patches on the first two terga. In the subspecies jidelis, the entire 

 tergum is yellow. In the extreme Southeast, the yellow on the terga 

 disappears on most specimens. 



Figures 71, 72. — Localities of: 71, C. bicornula bicornuta Guerin; 72, C. bicornuia fidelis 

 Viereck and Cockerell. 



Types. — The type female of C. bicornuta Guerin and the type male of 

 C. dujourii Guerin, both from New Orleans, La., are at the Museo 

 Civico di Storia Naturale, Genoa, Italy. The type male of C. venator 

 Cresson, from Illinois, is at the Philadelphia Academy of Natural 

 Sciences, no. 1937. The type male of C. curvicornis Cameron, from 

 Mexico, Presidio de Mazatlan (Forrer), is at the British Museum of 

 Natural History, no. 21.1,430. 



Distribution. — General over most of the United States and 

 northern Mexico. More common in the Central and Southern States. 



