WASP GENUS CERCERIS — SCTJLLEN 475 



the largest, the others small and fused at the base; antennae normal 

 in form, nearly black beyond the scape. 



Thorax black except for two elongate patches on the pronotum, 

 the metanotum, and patch on the propodeum, all of which are yellow; 

 tegulae low, smooth, and amber in color; enclosure ridged longi- 

 tudinally; mesosternal tubercles absent; legs largely yellow infused 

 with brown, basal segments very dark; wings subhyaline, slightly 

 clouded. 



Abdomen black except for a divided band on tergum 1, a wide but 

 deeply emarginate band on tergum 2, narrow bands on terga 3, 4, and 

 5; venter immaculate; pygidium with sides slightly convex and con- 

 verging to a rounded apical end. 



Male. — Length 13 mm. Body colors black with yellow markings, 

 legs with considerable amber; punctation somewhat coarse and 

 crowded; pubescence average. 



Head about one-seventh wider than the thorax; black except the 

 entire face, basal half of mandibles, and two basal segments of the 

 antennae, all of which are yellow; clypeal border with three distinct 

 dark fuscous denticles on the medial lobe; clypeal surface only slightly 

 convex; hair lobes cover only lateral clypeal lobes; mandibles mth 

 two denticles; antennae with the terminal segment curved. 



Thorax black except for two widely separated patches on the pro- 

 notum, the metanotum, and a small spot on the tegulae, all of which 

 are yellow; tegulae low and smooth; enclosure with a deep medial 

 groove and lateral ridges at a 45° angle to the base; mesosternal 

 tubercles absent; basal three segments of all legs yellow ventrally 

 and dark dorsally, tibiae and tarsi of the first two pair of legs largely 

 yellow; tibiae and tarsi of hindlegs dark; wings subhyaline. 



Abdomen black except for lateral patches on tergum 1, broad but 

 emarginate band on tergum 2, narrow bands on terga 3 to 6 and 

 lateral small patches on sternites 2, 3, and 4, all of which are yellow; 

 pygidium wdth sides subparallel but slightly convex and ends sub- 

 equal in width. 



C. dypeata prominens Banks is close to C. clypeata clypeata Dahlbom, 

 from which the former is separated by the more deeply emarginate 

 band on its second tergum. Some border hne specimens may remain 

 uncertain. The males are more difficult to separate than the females. 

 The females of C. atramontensis Banks and C. clypeata gnarina Banks 

 are also very close but easily separated by the characters given in the 

 key. 



Types.— The type female and allotype male of C. prominens 

 Banks, from Falls Church, Va., September and October, are at the 

 Museum of Comparative Zoology, Harvard, no. 13790. The type 

 female and allotype male of C. alaope Banks, also from Falls Church, 



