

HTMENOPTERA OF AMERICA. 



[part I. 



flavo-marginato ; seginentis teimiter flavo-limbatis ; seeuixlo sericeo, 



nitido, puuctato; alis subhyalinis. 



Zethus spinosus Sahss. Revue Zool. IX, 1857, 27<>. 



Total length, 13 mm. ; wing, S mm. 



9. Small, excessively rugose. Head large, dilated and con- 

 vex, densely cribrose with great pits; tare carrying a transverse 

 ridge, which covers the insertion of the antennae. Clypeus almost 

 transverse, convex, punctured, but much less rugose than the 

 head; covered with a pile of dull gray silky hair; its inferior 

 border entire; the middle of this border a little arched. Thorax 

 all cribrose with large sunken pits resembling a sieve. Its ante- 

 rior border carrying a transverse rim in the form of a quite pro- 

 minent lamina, which prolongs itself a little at the sides, descend- 

 ing along the margin of the prothorax. Post-scutel armed in the 

 middle with a spiniform sharp and raised tooth, or rather, with a 

 -pin.'. The concavity on the posterior truncated face of the 

 metathorax is divided by a furrow. The metathorax is very 

 angulate ; its lateral ridges very sharp ; its posterior concavity 

 very distinct, striate, bordered by two parallel longitudinal 

 ridge.-, beyond which the metathorax is again quite rugose. 

 Petiole as rugose as the thorax; its base alone smooth; its 

 expansion lengthened, cylindrical, but little contracted behind, 

 and cribrose with very large confluent punctures. Second seg- 

 ment globular-ovate, a little pediculate, its pedicle hardly equal- 

 ling a sixth the length of the segment. This segment is polished, 

 shining and sericeous, alt hough punctured, and appearing- as wide 

 as long when examined from above. 



[nseel black, with a transverse line on the face, a little dot 

 behind each eye. margin of prothorax, post-scutel, two pyriforni 

 line- on the metathorax and a line on the border of segments 1, 

 •J, :;, yellow. Sometimes also all the segments are bordered by a 

 yellow or ferruginous band, and the last segments now and then 

 ferruginous. Legs black; tarsi and tibiae garnished with silky 

 ferruginous hair: anterior knees spotted with yellow; interme- 

 diate tibia' with a yellow line; the femora with a spot at end. 

 Wing scales black, terminated behind by a yellow point by the 

 side of which is a little yellow process. Wings sub-smoky, with 

 brown nervures; the 2d cubital cell triangular, quite contracted 

 anteriorly. 



