ZETIIUS. 35 



post-scutel truncate, somewhat emarginate ; its angles seen from 

 before, elevated as two triangular teeth. Head and thorax quite 

 densely cribrose with very coarse confluent punctures ; the scutel 

 divided by a flat line. Metathorax coarsely but not so deeply 

 cribrose, short; its lateral edges very sharp ; the posterior face 

 having two strong vertical carinse, starting from the angles of 

 the post-scutel, but not going down to the extremity ; the channel 

 between them punctate ; the sides of thorax as cribrose as the 

 dorsum, those of the metathorax not quite so rough. Petiole 

 quite coarsely cribrose, rather bidentate, with the anterior side 

 polished, impunctate (as if smelted) as in aztecus, but the swelling 

 not cylindrical (as in aztecus) but oval, thick, and truncate as in 

 olomitus. The 2d segment subsessile (its form being a half 

 sphere), and punctured ; its second lamellar edge wide, getting 

 wider on the sides. The tirst border of the 3d segment advanced 

 in the middle ; the 2d lamellar border sinuate, advanced in the 

 middle, and emarginate on each side ; getting wider outside of the 

 emargination. The other segments very delicately punctate. 



Black ; the pilosity brown ; that of the abdomen long and f'll- 

 vous on the 2d and 3d segment. A line on the anterior margin 

 of the mandibles, two spots over the antenna?, anterior border of 

 prothorax ; two dots on the angles of scutel, two on the post- 

 scutel, posterior border of petiole, and submarginal border of 2d 

 and 3d segments, yellow. The posterior margin of prothorax and 

 the margin of the tegulse, brown; the second border of 2d and 

 3d segment piceous. Knees and tarsi brownish ; a yellow macula 

 at end of the 1st femora ; a yellow line on the 1st and 2d tibiae 

 outside ; this sometimes tawny. Wings clouded with brown, 

 with yellowish reflection. 



% . Clypeus rather rounded, black, very coarsely cribrose, its 

 inferior margin with three indentations in the middle, two little 

 carina? terminating in the external teeth; its surface very convex, 

 having a very prominent transverse swelling, somewhat like a 

 very obtuse carina ; a yellow triangle with the angle turned 

 downwards extends from that swelling to the end, and terminates 

 in the middle indentation of the inferior margin. Antennna 

 rather thickened, terminated by a short Particulate ferruginous 

 obtuse hook. 



Bess. a. diff. — This very remarkable species comes quite near 

 to Z. spinosus, from which it differs by its bidentate, not spined 



