112 GENERA OF HYMENOPTERA. 



Table of Genera. 



Petiole of abdomen biarticulate ; second subniarginal cell rcceivir.n both recur- 

 rent nervures Ammopliila Kirby. 



Petiole of abdomen uniarticulate 2. 



2.- Second submar>;iiial cell receiving both recurrent nervures. or the first re- 

 current nervure received at the intei-section of the first and second 



submarginal cells 3. 



Second and third subniarginal cells each receiving a recurrent nervure 4. 



3. — Prothorax narrowed anteriorly into a neck and longitudinally impressed 

 laterally ; antennae inserted low down on the face at the base of the 

 short transverse clypeus; he^d subtriangular when viewed from 

 above ; apex of third submarginal cell extending beyond the tip of 



the marginal cell Podium Latr. 



Prothorax scarcely narrowed anteriorly; antennae inserted on the middle of 

 the face, the clypeus being almost or quite as long as wide ; apex of 

 third submarginal cell not extending beyond the tip of the margi- 

 nal cell. 

 Black, with yellow markings ; clypeus bilobed at apex, less distinctly so 

 in the % ; petiole of abdomen as long as the entire thorax. 



Pelopcens Latr. 



Blue or violet, without pale markings ; clypeus tridentate at apex, that of 



9 sometimes with a small additional tooth on each side ; petiole of 



abdomen not as long as the metathorax C'halybion Dahlb. 



4. — Tarsal claws unidentate beneath ; anterior margin of clypeus with three 



teeth in %, and five in J ; petiole of abdomen a little longer than 



' posterior coxfe ; marginal cell extending a little beyond the third 



submarginal cell, the second submarginal narrow, twice higher than 



wide; color blue, green or violet C'llloriOll Latr. 



Tarsal claws bidentate Ijeneath. 



Petiole of abdomen more than twice the length of posterior coxse ; niar- 

 ginal cell not extending beyond the third submarginal cell : clyi)eus 

 of 9 with a notch in the middle of the elevated iinterior margin, 

 and a short tooth on each side of the notch; clypeus of % sim])le, 



or with a slight crenulation Isodontia Patton. 



Petiole of abdomen as long, or only a little longer than the posterior 

 coxae. 

 Marginal cell extending beyond the third submarginal cell : clypeus of 

 9 crenate on anterior margin, or with short broad teeth ; clypeus 



of % truncate, the margins crenu late JSphex Linn. 



Marginal cell not extending beyond the third submarginal cell ; clyi)eus 

 % 9 with a broad sinus on each side anteriorly, the central portion 



broadly produced and truncate Harpactopus Smith. 



Tarsal claws with five teeth beneath, the basal one very small ; petiole of 

 abdomen no longer than the posterior coxse ; marginal cell noi ex- 

 tending beyond the third submarginal cell ; clypeus of 9 produced 

 in its whole width, a deep notch in the middle, above which is an 

 elongated depression; cly})eus of % not so broadly produced, 



slightly sinuate anteriorly Priononyx Dahlb. 



The genus Ammophila is represented by about thirty species fri)m 



