58 HTMENOPTERA OP AMERICA. [PART I. 



yellow. The anterior margin of prothorax, two marginal spots 



on eacb wing scale, post-tegulae, two spots on post-scutel, two 



longitudinal fasciae on the tnetathorax, the end of petiole and the 



margin of the abdominal segment, yellow ; the lamellar margin 



of these also yellow or ferruginous, as well as the margin of the 



anus. A spot at the end of the femora and a line on the tibiaa 



of the first two pair, yellow. Wings subhyaline with brown veins; 



I 1 cubital cell subtriangular ; its radial tip very little trun- 



uil recurrent nerve inserted in the middle of the 



; [or margin. 



[less. a. diff. — This remarkable type has a certain resemblance 

 to the Eumenes of Division Zeta, because of its elongate linear 

 flattened petiole; bul this is not so much flattened, nor parted by 

 a furrow, but prismatic, and the head with its short mandibles is 

 (piite that of a Zeth us. 



It has ;l very near relationship to the Asiatic Labus but differs 

 itially by its prismatic petiole, a form which I have not yet 

 met with in the Wasp. 



/////. Chili. (This insect was given to me by the celebrated 

 oculisl and remarkable entomologist, Dr. Sichel, to whom it is 

 dedici 



Gen. DISCtELlUS Latr. 



Lip moderate. Labial palpi composed of four articles. Max- 

 illary palpi composed of six articles. Mandibles short, obliquely 

 truncate. Head often enlarged and a little emarginate behind. 

 Thorax lengthened, often angulate before. Abdomen pediculate; 

 the firsl segment transformed into a campaiiular or linear petiole. 



This genus differs from Zethus by its labial palpi composed of 

 four articles, and from Eumenes by the mandibles which are not 

 prolonged in the form of a beak. 



This genus connects it-elf to Zethus by its mandibles, and to 

 Eumenes and to Odynerus by its complete palpi; the forms of 

 its representatives are also intermediate, in some degree, to Zethus 

 and to Eumenes, ami somewhat to Nortonia and Zethus by the 

 subpediculate abdomen. The form of the thorax, often bordered 

 and angulated before, especially assimilates it to that which one 

 sees in the Zethus, 



