416 PROCEEDINGS OF THE ACADEMY OF [1899. 



impressed line anteriorly in middle, two impressed lines posteriorly; 

 scutellum with shallow punctures, scarcely impressed; postscutel- 

 lum prominent or subcarinate laterally, middle segment concave 

 medially, the concavity bounded outwardly by a more or less dis- 

 tinct carina, the two convexities irregularly rugose, separated from 

 sides by a comparatively indistinct carina; petiole short, cam- 

 panulate, stem slender fully as long as hind coxse and trochanters, 

 the enlarged portion Avith large separated punctures; second seg- 

 ment finely and closely punctured throughout, the pedicel short and 

 stout, much shorter than apex of petiole is wide, the body of the 

 segment more suddenly dilated than in cijlindricus, imperfedus; 

 radial side of second submarginal cell much less than the dis- 

 tance between the first transverso-cubital vein and the first recur- 

 rent vein on the cubital nervure; third submarginal somewhat 

 rhomboidal slightly larger above, the outer nervure gently sinuous. 

 Length 13-14 mm. 



Var. — Legs more or less dark ferruginous, the base of first or 

 second segments sometimes brownish. 



c?. — Front and clypeus without rugse; clypeus longer, rounded 

 at sides subemarginate between the lateral teeth ; tipi of antenna; 

 hooked, the last two joints of antennae quite small, the penultimate 

 the smaller, as to length ; middle segment supplied with two addi- 

 tional carinas wdiich border the concavity outwardly; second seg- 

 ment with larger, sparse, shallow punctures. Length 1 2 mm. 



Chapada, March. Five ?, one cf specimens. 



Zethus dubius Sm. 



Corumba, April. In the two specimens which I refer to this 

 species the postscutellum is tuberculate medially, and there is a 

 T-shaped carina between the insertion of antennre. The c? an- 

 tennae are hooked, with the last joint as long as preceding two 

 united. 

 Zethus hexagonus n. sp. 



Black; dot behind each antenna, one at each side of postscutel- 

 lum and a line (a little continued along sides) at apex of petiole, 

 yellow; legs from tips of femora reddish brown, which color some- 

 times extends obscurely to the coxre; wings fuscous, slightly coeru- 

 leous, quite dark in the costal cell. 



9. — Head above with strong separated punctures, on the front 



