o48 HTMENOPTEEA OF AMERICA. [PART I. 



Var. a. Clypeus with a yellow spot at summit. 



b. Head immaculate. 



c. Angles of prothorax black; its posterior margin nearly all 

 black. 



d. Metathorax black ; only the articular valves yellow. 



e. The fascia of post-scutel interrupted. 



f. Segments 3-5 narrowly margined with brown. 



g. Tibioe anteriorly obscure. 



%. Not quite as slender; thorax shorter. Second segment 

 more tuberculate at base. Clypeus pyriform, truncate, its apical 

 edge concave, hardly bidentate; its surface white, margined with 

 Mack. Antennae orange beneath ; the scape luteous beneath. 

 Mandibles immaculate ; head often immaculate; metathorax but 

 little maculate; coxa? 2-3 anteriorly luteous. 



Var. a. The femora with a yellow line near the apex> 



b. No spot under the wing. 



c. Clypeus quite yellow. 



d. Segments 3-6 narrowly margined with fulvous (only one 

 specimen). 



Var. 9 %. Ornaments dull yellow (from alteration?). 



Special Variety. — The margin of the second abdominal seg- 

 ment a little depressed or slightly canaliculate, mere coarsely 

 punctured, and even a little reflexed in %. In this variety the 

 yellow margin of the 2d segment is as broad as that of the first. 

 The anterior edge of prothorax is margined with yellow, and the 

 posterior one incompletely margined. (9 %, Orizaba.) 



Bess. a. cliff. — A species distinct by its elongate slender form, 

 its black shining body, cribrose with punctures like fine strings, 

 and smooth metathorax; as also by its scarce ornaments, straw- 

 vellow and with only two abdominal fasciae, the hinder margin 

 of prothorax being bordered with yellow. It is very similar 

 to 0. Tacubayse, but much larger, and more strongly punctured; 

 the abdomen is not so elongate, the 2d segment is scarcely longer 

 than broad, posteriorly truncate, not arcuate, etc. 



144. O. COyottlS Saups. (Fig. 26.)— Niger, minutus, abdomine gracili ; 

 corpore subrupose punctato ; metanoto tennissime punotato ; abdominis 

 seementis lO, 20 valde punctatis : secundo ba?i constricto ; scaposubtus, 

 puncto frontali, oculari et post-ocniari, pronoti margine antico et postico 

 temiissime, punctis 2 post-scutelli abdominisque segmentorum l l , 2 l 



