294 SPHEGIDiE. 



Head large, wider than the thorax, siibglobose ; eyes emarginate 

 or SLibeiiiargiuate within, in some Oriental species barely so ; ocelli 

 in a triangle forward on the vertex ; antennae 

 inserted high up about the middle of the face 

 and Mide apart from each other ; clypeus broad, 

 with a lobe on each side ; mandibles acute, 

 the labrum concealed ; thorax ovate, pronotum 

 transverse ; median segment obtusely rounded, 

 sometimes steep posteriorly ; legs stout, spinose, 

 anterior tarsi ( 5 ) strongly ciliated : wings o£ 

 mUavfhus avidus, moderate length ; fore ^ing with one radial and 

 2. }. three cubital cells, radial cell narrow, elongate, 



and acuminate at apex ; the 1st cubital cell 

 measured on the cubital nervure about twice the width of the 2nd, 

 the 2nd cubital cell narrowed at top, below receiving the 1st 

 recurrent nervure in or a little past the middle, the 3rd cubital 

 cell half the wddth at top that it is below, receiving the 2nd 

 recurrent nervure near its base ; abdomen with the 1st segment 

 normal, or narrowed and subpetiolate at base. 



KeT/ to the Species. 



A. First segment of the abdomen not narrowed 

 at base into a petiole. 



a. Apical margins of abdominal segments 2-5 



broadly depressed and finely transversely 



striate P. nigriceps, p. 295. 



b. Apical margins of the abdominal seg- 



ments not depressed. 

 a'. Clypeus with its anterior margin bi- 

 sinuate. 

 a^. Abdomen for the greater part fer- 

 ruginous red : wings fiavo-hyaline . P. depredator^ p. 295. 

 6^. Basal segment of abdomen onlj^ fer- 

 ruginous red ; wings fuscous P. hasalis, p. 296. 



b' . Clypeus arched anteriorly. 



a^. Abdomen with transverse ;yello wish- 

 white lines on the apical margins of 

 segments 2-4. 

 a^. Median segment rounded, with a 

 narrow medial longitudinal fur- 

 row P. ordinarius, p. 296. 



6*. Median segment truncate poste- 

 riorly, witli a broad medial longi- 

 tudinal fuiTow P. avidus, p. 297. 



6^. Abdomen with large lateral spots on 



the basal 4 segments P. elegans, p. 297. 



c^. Abdomen with the apical margins of 



the basal 3 segments ferruginous . . P. sulphureus, p. 298. 



B. First segment of the abdomen narrowed at 

 base into a petiole. 

 a. Clyppiis carinate down the middle, head 

 and thorax finely punctured. Length 

 $ 11-12 mm P. concinnus, p. 298. 



