48 HYMENOPTERA OF AMERICA. [PART I. 



41. Z. aiiruleiitus Sauss. 



Zethus aurulens Sauss. Vespides, III, 121, 8, pi. vi, fig. 5, 9> 1854. 



Hub. Brazil. 



42. Z. Matzicatzin Sacss. — Niger ; capite discoidali, lato, facie 

 cribrata, vertioe supra inflato, minus cribrato; ocellis in declivitate 



frontis sitis ; thorace grosse cribrato, postscutello truncato, postice ex- 

 ciso, carinato; metanoto sulco conspicuo, at foveola nulla; infra valde 

 striato, supra laevi, in medio bicarinato ; petiolo polito impunctato, vaMe 

 inflato, apice puncto maximo impresso; secundo segmento longe pedun- 

 culato, medio margine impresso, cum reliquis rufo ; tertio puuctato, in 

 medio prodncto; punctis frontalibus et post-ocularibus 2, pronoti 

 margine, macula subalari et maculis 2 scutelli, limboque segmentorum 

 1, 2, flavis ; tibiis rufis ; alis fusco-flavescentibus. 

 £ . Scutello piano, tenuiter puuctato, infra macula lsevi et margine in 

 medio subproducto ; antennarum scapo subtus flavo. 



Zethus Matzicatzin Sacss. Revue et Mag. de Zool. 1857, 271. 



Total length, 18 mm. ; wing, 11 mm. 



Mandibles obliquely truncate, trenchant, without teeth, but 

 with a single lobe. Head very large, much wider than thorax ; 

 face flattened; ocelli arranged in a broad triangle and placed, 

 not on the summit, but on the slope of the vertex. Vertex 

 strongly enlarged transversely behind the ocelli, but swelled 

 upward. Face*offering between the antennae two little vertical 

 carina?. Thorax very short, quadrate, depressed; the margin of 

 the prothorax little prominent. Disk of the mesothorax wider 

 than long ; its anterior curve describing a semicircle, not an 

 ellipse as in all the preceding species. Scutellum divided by a 

 channel. Post-scutel truncate, angulate; its posterior border 

 offering a concavity and carrying an arcuated ridge interrupted in 

 the middle (which especially distinguishes it from the preceding 

 species, which has the post-scutel whole rounded above). Meta- 

 thorax very angulate, having four sharp ridges, so to speak : 1st, 

 the two ordinary lateral ones, which here form two sharp crests ; 

 2d, two other very short ones, which start from the angles of the 

 post-scutel ; the middle divided by a strong channel, but, properly 

 speaking, without any concavity. The summit of the metathorax, 

 especially the space situated on each side between the two ridges, 

 is smooth, shining, not punctured (or very finely striated), the 

 remainder wrinkled. The flanks under the lateral ridcres smooth 



