1899.] NATURAL SCIENCES OF PHILADELPHIA. 411 



Chapada, February, March. Fifteen ?, five cf specimeus. 

 The almost sessile second segment, and minute apical anteunal 

 joint of male, readily distinguish this species. The male cly- 

 peus is sometimes marked anteriorly with yellow. 



Zethus fraternus Sauss. 



Chapada, February to April, December; Pedra Branca and 

 Corumba, April; Santarem. Twenty-three ?, six c?* specimens. 

 The yellow dots above iusertiou of antennae are frequently entirely 

 absent. 

 Zethus rufipes n. sp. 



Black; mandibles medially, anterior margin of clypeus, base of 

 autennse, spot on scape at apex beneath, and legs except coxte, 

 ferruginous; a dot on front behind each antennte and line at apex 

 of petiole (not extending on sides), yellow; wings dark violaceous 

 throughout. 



cf. — Head with strong but not deep punctures, closest and small- 

 est on front; a faiut carina connects the bases of the antcunre; cly- 

 peus with separated punctures, about one-third longer than 

 broad, its fore margiu truncate, and armed with two widely sepa- 

 rated teeth; space between hind ocelli equal to about two-thirds the 

 distance between them and eyes; antennre rather long, the scape 

 not much longer than the pedicel and following two joints imited, 

 first joint of flagellum distinctly longer than joints two and three 

 united, ultimate joint as long as, or longer than, the two preceding, 

 the tip of antenna not curled, but hooked ; prouotum sharply mar- 

 gined anteriorly, not dentate laterally, strongly punctured ; dorsu- 

 lum similarly punctured, with a smooth, slightly raised line ante- 

 riorly in the middle, and posteriorly with two strongly impressed 

 lines which diverge anteriorly ; scutellum impressed; postscutel- 

 lum entire; middle segment rugoso-punctate except the nearly 

 smooth sides and two areas on upper surface laterally, broadly and 

 deeply sulcate down middle, the upper surface separated from the 

 sides by an indistinct carina; stem of petiole about as long as first 

 hind tarsal joint, stout, the swollen portion elongate-ovate, with 

 large, widely separated punctures; pedicel of second short, its 

 length not equal to width of apex of petiole, the body of the seg- 

 ment gradually dilated very much as in fraternus, with sparse shal- 

 low punctures above, and an oblique linear impression on each 



