358 HYMENOPTEKA. 



the middle ; the lateral furrow oblique, wide, and not very deep. Suturiform articula- 

 tion slightly curved, not very wide or deep, and shining, impunctate ; the second 

 furrow shallow. 



C. Abdomen, and the thorax more or less, vermilion-red. (Species 42-49.) 



1 (8). Suturiform articulation crenulated. 



2 (7) . Mesonotuni, except a black line at the tegulae, red. 



3 (4) . The depression on either side of the keel wide, deep, continuous with 



the oblique lateral one ; the keel sharp, reaching quite near to the 



apex ; ovipositor not much longer than the abdomen megaptera. 



4 (3). The depression on either side of the keel shallow, not continuous with 



the lateral one ; ovipositor as long as the body. 



5 (6). Face irregularly striated ; lateral branches of the suturiform articula- 



tion striated abjectus. 



6 (5). Face not striated; lateral branches of the suturiform articulation not 



striated vagabundus. 



7 (2) . Thorax entirely black bilimeki. 



8 (1). Suturiform articulation not crenulated or striated. 



9 (14) . Mesonotum in front red. 



10 (11). Palpi black; pronotum, the greater part of the mesonotum, scutellum, 



and metanotum red ; ovipositor longer than the body salvini. 



11 (10). Palpi white; mesonotum reddish in front. 



12 (13). A stout keel in the middle of the suturiform articulation .... infirmus. 



13(12). No keel in the middle of the suturiform articulation fuscipalpis. 



14 (9) . Thorax black gravidus. 



1. Suturiform articulation crenulated. (Species 42-45.) 



42. Iphiaulax megaptera. (Tab. XV. fig. 5, ? .) 



Tiger, mesonoto abdomineque rufis ; alis magnis, fuliginosis ; terebra quam corpus breviore. $ . 

 Long. 10 millim. ; terebra fere 8 millim. 



Hal. Mexico, Tacubaya (Bilimelc). 



Face opaque, impunctate, sparsely covered with whitish hair ; front broadly, but not 

 deeply, depressed above the antennae, without any central furrow ; tips of the mandibles 

 piceous. Antenna? stout, microscopically pilose ; the third joint a little longer than the 

 fourth, and narrowed in the middle. Thorax shining, impunctate. Metanotum with 

 rather a steep slope from the middle. Petiole semiperpendicular ; the two furrows on 

 the same level, wide and deep, the outer one ending a little in front of the middle, the 

 dividing partition stout. Second segment with a stout, broad keel down the centre, 

 reaching nearly to the apex ; a large oblong depression on each side of it, uniting at 

 the base with a wider depression, which latter goes somewhat obliquely down the sides ; 

 transverse furrow moderately wide, stoutly, longitudinally striated, the apical branch 



