ISG').] 125 



Three 5 specimens ; % unknown. Closely resetobles the preceding 

 species in ornamentation ; but readily distinguished by the very promi- 

 nent, bidentate projection of the clypeus. This species may possibly 

 prove to be the $ of 0. deserta Say. 



18. Cerceris deserta. Say. 



Ccrccris dcscrta. Say, Long's Second Expedition, ii, p. 34.3, % . 

 Black, finely punctured; face, scape in front, two spots on collar, tegulse, 

 postscutellum, most of legs, and narrow bands on abdomen, yellow; wings 

 fusco-byaline. 



Malf. — Black, rather finely and spai'sely punctured, especially the 

 abdomen, thinly pubescent ; the face entirely, mandibles except tips, 

 and the scape in front, bright yellow; antennae dusky above, black at 

 base, the flagellum fulvous beneath. Thorax : the mesothorax and 

 scutelluni sparsely punctured ; a spot on each side of the collar, some- 

 times much reduced, spot on tegulae, and a transverse line on the post- 

 scutellum, yellow; the basal enclosed space of the metathorax chan- 

 nelled down the middle, with a few oblique striae on each side. Wings 

 fusco-hyaline, slightly violaceous, darker at tips ; nervures pale ferru- 

 ginous. Legs yellow ; the four anterior femora behind, apical half of 

 the posterior pair, as well as the tips of their tibiae, black, their tarsi 

 dusky. Abdomen rather feebly and sparsely punctured, the segments 

 convex, and rather strongly contracted at base ; the basal segment 

 generally, but not always, with a yellow spot or dot on each side ; the 

 five following segments each with a narrow, continuous, subapical, yel- 

 low fascia, more or less narrowed in the middle and rather the broadest 

 on the anterior segments ; beneath, the second to fifth segments have 

 generally a yellow transverse spot or dot on each side. Length 4 J 

 lines; expanse of wings 8 lines. 



Hah. — Massachusetts (Ridings); Pennsylvania (Cresson) ; Dela- 

 ware (Dr. Wilson ) ; Illinois (Dr. Lewis). Coll. Ent. Soc. Philad. 



Eight % specimens; $ unknown. 



19. Cerceris imitator, n. sp. 



This species diifers from C dexcrta principally in the punctation 

 being much closer, deeper and coarser ; the size is smaller, the en- 

 closed basal space of the metathorax is longitudinally striated, the pos- 

 terior femora and tibiiis have always a larger proportion of the black 

 color, and the basal segment of the abdomen, and the venter, are im- 

 maculate. Length 4 lines; expanse of wings 7 lines. 



//'</>.— Illinois (Dr. Lewis). Coll. Ent. Soc. Philad. 



Eight % specimens; 9 unknown. This is, no doubt, the var. ,5 of 

 Say's deserta, and is at once distinguished from that species by tjift— 

 coarse sculpture. 



