J. C. HUTSON 217 



3. Claws simple, without a tooth beneath; tibiae more or less spinous; tarsal 



comb in female present; abdomen most frequently very elongate, the 

 petiole composed of two segments, rarely only of one segment; cubital 

 vein of hind wings usually originating bej-ond the transverse median 



vein Sphecinae {Ammophilinae of Authors) 



Claws simple with a single tooth beneath, although sometimes verj^ minute; 

 hind pair with or without a tooth ; tarsal comb in female absent ; abdomen 

 always with one-segmented petiole; cubital vein of hind wings interstitial 

 or nearly so 4 



4. Antennae inserted on the middle of the face; metathorax with a large 



U-shaped area above; mesopleura not longer than the height of the 



thorax Sceliphroninae 



Antennae inserted far anterior to the middle of the face, on ur just aljove an 

 imaginary line drawii from base of eyes; metathorax without a large 

 X^-shaped area above; mesopleura much longer than the height of the 

 thorax Podiinae 



Key to Genera of Subfamily Sceliphroninae 



Second cubital cell receiving both recurrent veins. 



Species black and yellow, not metallic; clypeus flat, bidentate at apex; 

 transverse median vein in front wings not interstitial with basal vein, but 

 uniting with the median vein a little before the origin of the basal nervure; 

 petiole of abdomen about twice as long as the median segment. 



Pelopaeus Latreille 



Species metallic blue or \'iolaceous; clypeus normally tridentate anteriorh-; 



transverse median vein in front wings interstitial with the basal vein; 



petiole of abdomen not longer than median segment. .Sceliphron Klug 



Table of Species of Sceliphron 



1 . Females 2 



Males 3 



2. Abdomen with pubescent spot on third and fourth ventral segments; body 



hairs almost entirely dark cyaneum Klug 



Abdomen without pubescent spot on third and fourth ventral segments; 

 whitish hairs on dorsum of median segment. . . . zimmermanni Dahlbom 



3. Body dark blue black or blue green, hairs almost entirely dark. 



cyaneum Klug 



Body paler, hairs almost entirely whitish, wings fuliginous to liyaline with 



fuscous tips zitmnermanni Dahlbom 



Genus SCELIPHRON King 

 Sceliphron Klug, Ncu.schrift Ges. Naturf. Frciuuk', Berlin, iii, ISOI, ")(il. 

 Chalyhion Dahl., Hym. Eur., i, 1843, 21. 

 Chalyhion Patton, Proc. Host. Soc. Nat. Hist., xx, 1880, 378. 



Genotype — Chalyhion caeruleuni {=cijaneum Dahlbom), des- 

 ignation of Patton. 



TRANS. AM. ENT. .SOC , XLV. 



