462 PROCEEDINGS OF THE NATIONAL MUSEUM vol. 90 



medially, the depression broadest anteriorly, bisected by a median 

 longitudinal carina, the two sections of the depression more or less 

 foveolated; posterior coxa large, with a more or less prominent pro- 

 tuberance near apex on the inner dorsal margin; posterior femur 

 rather broad, with a single tooth on ventral margin beyond the middle; 

 posterior tibia with two moderately long, unequal spurs located at the 

 apex; fore wing extending beyond apex of abdomen; marginal vein 

 usually about half as long as submarginal; postmarginal vein shorter 

 than marginal; stigmal vein at least a little shorter than postmarginal; 

 abdomen sessile, never strongly compressed or depressed, and approxi- 

 mately as long as head and thorax; posterior margins of tergites 

 (except sometimes the third tergite) not emarginate; ovipositor always 

 prominently exserted. 



KEY TO THE SPECIES OF MONODONTOMERUS IN THE UNITED STATES NATIONAL 



MUSEUM 



1. Scutellum, behind cross furrow, smooth and polished except for 



a few weak lines laterally 12 



Scutellum, behind cross furrow, distinctly sculptured, sculpture 

 usually weaker medially than laterally and occasionally with 

 a median area quite smooth 2 



2. Malar furrow absent or impressed for only a very short distance 



adjacent to eye margin; face convexly swollen below an- 

 tennae 11 



Malar furrow present and complete; face flat or nearly so, at 

 least not markedly swollen 3 



3. Ovipositor obviously shorter than abdomen 4 



Ovipositor at least very nearly as long as abdomen, usually as 



long as abdomen or longer 9 



4. First tergite with very shallow but rather distinct reticulation 



over its dorsal surface 1. dianthidii, new species 



First tergite dorsally without sculpture 5 



5. Fore wing without a stigmal cloud; propodeum basally on each 



side of median carina with a broadly rounded and rather deep 

 depression behind which is a less well defined and much smaller 

 depression; funicle joints, except first, broader than long; ovi- 

 positor about half as long as abdomen 2. aereus Walker 



Fore wing with a distinct cloud at stigmal vein; propodeum 

 with median depression elongate and narrower; funicle joints 

 rarely broader than long; ovipositor usually but not always 

 more than half as long as abdomen 6 



6. Middle and fore legs, except their coxae, entirely reddish yellow; 



ovipositor less than half as long as abdomen cubensis, new species 



Middle and fore femora always metallic or black; ovipositor 



about two-thirds as long as abdomen 7 



7. Scape metallic green; posterior tibia, except at base and apex, 



metallic green and middle and anterior tibiae more or less 



tinged with metallic 4. viridiscapus, new species 



Scape testaceous, sometimes washed with metallic toward apex; 



all tibiae reddish testaceous 8 



