feknald: sphecidae from argentine. 265 



Mesonotum rising but little above the top of the collar, with a pronounced median 

 depression nearly reaching the posterior edge of the plate, which is strongly trans- 

 versely striate, the striations being slightly oblique in front and markedly so near 

 the middle line behind. Scattered punctures are also present. Scutellum consid- 

 erably higher in the middle than the mesonotum, with a median depression form- 

 ing a pair of quite smooth, glistening projections, which are quite noticeable and 

 almost large enough to be described as bituberculate. Sides of the scutellum stri- 

 ate and closely punctured. Postscutellum narrow, with no median depression, 

 closely punctured. Dorsum of median segment long, with a faint median depres- 

 sion and its lateral lines depressed ; its surface closely, transversely striate, and 

 bearing numerous quite long, black hairs. Posterior end and sides similarly stri- 

 ate and with similar hairs, the striations extending down across the metapleura. 

 Mesopleura and mesosternum coarsely and closely punctured except in front of 

 the coxae. Petiole short, rather stout, almost straight, two-thirds as long as the 

 hind metatarsus, equal to the second hind tarsal segment in length, with small, 

 scattered punctures. 



Abdomen black but with a faint ferruginous tinge, rising high and almost per- 

 pendicular from the petiole, smooth and glistening. Stigma of the second abdomi- 

 nal plate close to the anterior margin. Dorsal plate minutely, sparsely punctured, 

 some of the punctures forming a row on each side of the middle line, nearly par- 

 allel to and a little distance in front of, the posterior margins of the plates. A 

 similar arrangement of the punctures occurs below, except that there they form 

 a narrow band instead of a row. Last dorsal and ventral plates with scattered, 

 coarser punctures, and a few black hairs. 



Wings uniformly fuliginous, with a slight greenish reflection except outside the 

 cells, where it is very faint or absent. First and second transverse cubital veins 

 of the fore wing each with a bulla near the cubital. Radial cell rather short, its 

 end rounded. Cubital vein almost obsolete beyond the third cubital cell. A bulla 

 is present in the transverse cubital vein of the hind wing. Tegulae black, glisten- 

 ing, with a few scattered punctures. 



Legs black, very faintly tinged with ferruginous, the tarsi and the middle and 

 hind tibiae somewhat grayish sericeous. Fore metatarsus with eight comb teeth, 

 the first shorter than the others. Posterior face of hind tibiae coarsely brown 

 sericeous. Claws with three teeth evident and one (the inner) microscopic. Tips 

 of the claws ferruginous. 



The male differs as follows : — Clypeus and frons with traces of silvery pubes- 

 cence. Clypeus elongated, its anterior margin slightly, broadly excavated, not 

 reflexed. Inner margins of eyes very slightly approaching downward. Frontal 

 suture not developed in the ocellar area. First and second segments of the an- 

 tennal filament short, together a very little longer than the third. Distance 

 between the lateral ocelli about equal to that between them and the eyes. Cheeks 

 retaining their greatest width well down before narrowing. Mandibles with less 

 of the ferruginous tinge. 



Dorsal edge of the collar and sides of the mesonotum with faint traces of short 

 silvery hairs suggesting pubescence there in fresh specimens. Scutellar projec- 

 tions less marked than in the female. Sixth ventral abdominal plate rather nar- 

 rowly, deeply excised behind, and covered with short brownish hairs. Claws with 

 four teeth, the inner one, though smaller than the others, being perceptible in 

 favorable specimens. 



