26 HYMENOPTERA OF AMERICA. [PART I. 



punctured, but not more on its margin than elsewhere ; the third 

 segment densely punctate; the following impunctured ; the first 

 margin of the 2d a little arcuate and depressed in the middle ; 

 the second lamellar margin of 2d and 3d segment growing a little 

 wider on the sides; that of the 3d rather transversely cut out in 

 the middle third. Posterior tibiae arcuated, a little deformed. 



Black, with a very dull silky reflection, rather fulvous. Mouth, 

 mandibles, and clypeus, yellow, a little orange, or reddish at top 

 of clypeus. Scape and the end of flagellum beneath, yellowish 

 or tawny. Two spots over the antennae, two lines on the vertex 

 starting from the eyes, and two lines behind the eyes, not marginal, 

 tawny. Both margins of prothorax and two spots on the lateral 

 margins of scutellum, yeliowish-tawny ; two spots on the edges 

 of post-scutel, the margin of petiole and a narrow yellow sub- 

 marginal line on the second segment, yellow; anterior feet more 

 or less ferruginous or yellow-tawny beneath. Wings subhyaline ; 

 veins brown ; 2d cubital cell lengthened at base (on the side 

 looking to the base of the wing). 



9. Clypeus rounded, densely and strongly punctured; a little 

 velutinous ; its inferior margin arcuate, not truncate nor emargi- 

 nate; its summit a little carinate. The head beneath and around 

 the mouth, post-sternum and anterior coxae, sulphur-yellow. 



% . Clypeus a little wider, having the same shape and color as 

 in the ?. The oblique cutting border of mandibles with but 2 

 little notches. Antennae tawny beneath ; the last two joints obtuse, 

 forming nearly a hook. Anterior tibias, tarsi, and thighs beneath 

 ferruginous; intermediate tibiaa beneath and 1st, 2d, and 3d joints 

 of the tarsi beneath yellow ; the 3d segment slightly margined 

 with yellow. 



Var. Prothorax black, with its angles and two marks, tawny. 



Bab. Mexico. The Oriental Cordillera. Orizaba (Mr. Sunii- 

 chrast). 



items', a. cliff. — This is a very distinct species in the remarka- 

 ble form of its metathorax and the rugosities of its petiole; quite 

 different from all other Mexican Zethux, except from clyjyeatus. 

 It differs by its more excavated metathorax. the excavation being 

 polished and more carinated, and by its prothorax, more rounded 

 anteriorly, not square shaped nor crested on the sides ; by its 

 rougher petiole, carinated in the middle, etc. It has such 

 an extraordinary resemblance to Z. miniatus that it might be 



, 



