96 E. T. CRESSON. 



One S specimen. A beautiful little species, with handsomely orna- 

 mented body and wings. 



C. Body black, marked or banded with ivhite or yelloio. 



28. Pompilus biguttatus. 



Pompilus biguttatus, Fabr., Ent. Syst. Suppl. p. 249; Syst. Piez. p. 193. Say, 

 Bost. Jour. Nat. Hist, i, p. 303. 



Fompilus o-)iotatus, Say, Bost. Jour. Nat. Hist, i, p. 304, (var). 

 Female. — Black, sometimes covered with a grayish-sericeous pile ; 

 head with narrow Avhite orbits, interrupted above, sometimes very in- 

 distinct, or entirely wanting; anterior margin of the clypeus ronnded 

 or subtruneate, reflexed ; posterior margin of the prothorax arcuate, 

 sometimes margined with white, generally interrupted in the middle, 

 or entirely wanting; in some specimens the tegulae have a white spot; 

 sides of the scutellum and the metathorax more or less silvery ; legs 

 more or less grey -sericeous, anterior tarsi strongly ciliated, tibiae and 

 tarsi strongly spinose, the extreme tips of the anterior tibiae are some- 

 times white, and their tarsi sometimes brownish; in one specimen with 

 immaculate abdomen, the posterior tibiae have a white line at extreme 

 base; tarsal claws cleft as in % ; wings vary from fuscous to hyaline, 

 always more or le.ss blackish at tips, with the violaceous reflection more 

 or less conspicuous, third submarginal cell shorter than the second, 

 sometimes nearly quadrate, but generally narrowed towards the mar- 

 ginal; abdomen elongate, convex, acuminate at tip; first segment 

 sometimes clothed with an appressed silvery pile, immaculate; second 

 segment with a transverse white spot on each side at base, sometimes 

 reduced to a dot, or entirely wanting; third segment also with a trans- 

 verse white spot on each side at base, sometimes confluent and forming 

 an uninterrupted band, sometimes these spots are reduced to dots, or 

 are entirely wanting; fourth segment with a transvei'se, white line ou 

 each side at base, sometimes almost confluent, and sometimes obsolete 

 or entirely wanting; sixth segment has sometimes a white spot on the 

 disk ; venter immaculate. Length 4 — 7 lines. 



Male. — Much smaller and narrower than the $ , much more silvery, 

 especially the face, prothorax and metathorax; the prothorax is gene- 

 rally margined posteriorly with white, which is sometimes subobsolete 

 or entirely wanting; the anterior tibise and tarsi are sometimes tinged 

 with ferruginous, the former often tipped with white; the posterior ti- 

 biae have generally a white line at base above, and the tibial spurs are 

 sometimes entirely white ; the wings are more hyaline, iridescent, the 

 tips are always margined with fuscous; the abdomen is flattened, the 

 second segment has generally a white dot on each side, while the third 



