466 hymenoptera. 



110. Cerceris nigrescens. B.M. 



Female. Length 5 lines. — Black : the sides of the face and 

 the clypeus pale yellow, the margins of the latter black; the 

 mandibles yellow at their base ; the clypeus transverse, project- 

 ing from its base, very obsoletely emarginate in front; the fla- 

 gellum slightly fulvous towards the base beneath. Thorax : a 

 minute spot on each side of the collar, another on the tegulae 

 and the post-scutellum, yellow ; the mesothorax sparingly punc- 

 tured, the metathorax strongly so, the subcordiform space at the 

 base longitudinally striated ; the anterior and intermediate tibia 

 in front yellow ; the tarsi ferruginous ; the posterior legs entirely 

 black ; the wings subhyaline, the nervures ferruginous. Abdo- 

 men : the basal segment with a yellow spot on each side, the 

 following segments with uninterrupted fasciae narrowed in the 

 middle ; beneath, entirely black. 



Hab. Nova Scotia. 



111. Cerceris Dufourii. 



Cerceris Dufourii, Guer. Icon. Reg. Anim. 444. 

 Hab. New Orleans. 



112. Cerceris verticalis. 



Female. Length 6 lines. — Black, thickly punctured ; the head 

 ferruginous behind the eyes ; the scape and second joint of the 

 flagellum ferruginous ; the face below the antenna; yellow ; the 

 margins of the clypeus black ; the mandibles ferruginous, their 

 extreme base yellow. Thorax : the collar yellow, interrupted 

 in the middle by a ferruginous spot ; the post-scutellum and a 

 spot on the tegulje yellow ; a large ferruginous blotch on each 

 side of the metathorax ; the wings smoky-hyaline ; the legs fer- 

 ruginous. Abdomen : the basal segment ferruginous, with a 

 minute yellow spot on each side; the second segment yellow, 

 with the basal margin and a produced quadrate spot in the 

 middle ferruginous ; the margins of the following segments with 

 a narrow band which is widened at the sides ; beneath, rufo- 

 piceous, brightest at the base. 



Hab. Georgia. (Coll. F. Smith.) 



113. Cerceris BicoRNUTA. B.M. 

 Cerceris bicornuta, Guer. Icon. Reg. Anim. 443. 



Hab. United States (New Orleans ; Georgia; Delaware). 



This species is very variable in colouring, the abdomen and 



