606 PROCEEDINGS OF THE NATIONAL MUSEUM. T0L.e3. 



distinctly broken at or somewhat below middle and postf ureal; 

 first tergite with the spiracle at or but slightly beyond the middle, 

 petiole rather thick and deeply sulcate laterally, ventral edges of 

 tergite widely separated and subparallel, tergites beyond second 

 strongly compressed ; head and thorax very finely pimctate and clothed 

 with very short, dense, silky pubescence. 



KEY TO NORTH AMERICAN SPECIES. 



Petiolar area nearly as long as areola; first and second tergites tipped with red, 

 the postpetiole strongly longitudinally rugulose; second tergite much less 

 than twice as long as basal width, its sides widely divergent; second abscissa 

 of radius nearly straight at base; ovipositor less than t^vice as long as first 

 tergite hrevicauda, new species. 



Petiolar area a third or less as long as areola; first and second tergites entirely 

 black; the postpetiole at most weakly aciculate; second tergite about twice 

 as long as basal width with sides nearly parallel; second abscissa of radius 

 distinctly outcurved at base; ovipositor about three times as long as first 



tergite 1. 



I. Malar space much less than half as long as basal width of mandible in female, 

 sometimes half as long in male; hind legs stout, femur nearly one-third as 

 broad as long, basitarsus much less than half as long as tibia, all tarsal joints 

 together in female about as long as tibia, in male slightly longer 



radiolatKS (Provancher), 



Malar space about as long as basal width of mandibles in female, longer in male; 

 hind legs slender, femur hardly one-fourth as broad as long, basitarsus nearly 

 half as long as tibia, all tarsal joints together in both sexes much longer than 

 tibia gracilipes, new species. 



PSEUDERIPTER>fUS BREVICAUDA, new species. 



Female. — Length 7 mm., antennae 5.5 mm., ovipositor 1.6 mm. 

 Head, except occiput, very finely, densely granular; face elevated in 

 middle, weakly impressed below antennae, with prominent, median 

 tubercle above; malar space scarcely a third as long as basal width of 

 mandible; interfoveal line (shortest distance between cl3'peal foveae) 

 twice as long as foveo-ocular line (shortest distance between fovea 

 and eye); eyes very weakly emarginate opposite antennae; posto- 

 cellar and ocell-ocular lines equal and scarcely twice as long as diam- 

 eter of a lateral ocellus. Thorax very minutely punctate, mesono- 

 tum subpolished; mesopleural suture broadly foveolate; propodeal 

 carinao very strong, the areola scarcely a half longer than petiolar 

 area, apical areas strongly rugulose; wing with radial cell rather 

 acute at apex, base of second discoidal cell scarcely half as long as 

 second recurrent vein; ncrvellus interstitial, broken at middle; 

 legs, especially hind legs, short, the hind femur about a third as broad 

 as long; hind basitarsus about two-fifths as long as tibia, fifth joint 

 nearly as long as third. Abdomen barely a third longer than head 

 and thorax united ; first tergite rather stout, its sides nearly straight, 

 about half as wide at apex as long, its spiracle distinctly beyond 

 middle, carinao and fovea© of petiole very strong; second tergite 



