362 HYMENOPTERA. 



jecting; front finely rugose, the central furrow distinct; vertex obscurely aciculated. 

 Abdomen a little longer than the head and thorax together. Petiole semiperpen- 

 dicular ; the central part narrow at the base, becoming gradually broader towards the 

 apex ; the inner furrow wide, moderately deep, impunctate, the outer furrow much 

 narrower. Second segment with a sharp keel down the basal three fourths, the keel 

 bounded by a narrow furrow ; the lateral depression curved, of nearly equal width 

 throughout. Suturiform articulation shallow, moderately broad ; the second and third 

 articulations much narrower. 



A stouter and larger species than I. infirmus ; the head and thorax much more 

 densely and uniformly pilose ; the abdomen wider, if not shorter ; the lateral depression 

 on the second segment deeper and reaching nearly to the apex ; the central keel stouter ; 

 the transverse furrow on the apex of the second and third segments much less distinct. 

 In both species the stigma and nervures incline to fuscous. 



49. Iphiaulax gravidllS. (I. capetillensis, Tab. XIV. fig. 24, 6 .) 



Tiger, abdomine ferrugineo ; alis fumatis. S • 

 Long. 9 millim. 



Edb. Guatemala, Cerro Zunil 4000 feet [Champion). 



Antennse as long as the body, tapering slightly towards the apex ; basal joint 

 produced at the apex beneath. Face transverse, semiopaque, aciculate, clypeus not 

 projecting at the apex, front depressed in the middle, the furrow wide, finely rugose. 

 Abdomen a little longer than the head and thorax together, not much wider than the 

 mesothorax. Petiole semiperpendicular ; central portion pear-shaped ; the inner furrow 

 narrow, its outer keel higher than the centre of the petiole, the outer furrow somewhat 

 narrower. Second segment with a stout keel in the centre, the keel extending a little 

 beyond the middle, the bounding furrows narrow ; lateral depression oblique, deep. 

 Suturiform articulation narrow ; second articulation not much narrower than the first, 

 and placed a little before the middle of the segment ; the third articulation a little 

 narrower than the second, and situated not so far forward. 



/^ The group of I. ckuentatus. 



The area on the second segment wedge-shaped, longer than broad, the depression on either 

 side of it narrow and not very deep, the surface of the latter rough ; the lateral 

 furrow oblique, straight ; suturiform articulation longitudinally striated, as is also 

 the next furrow. Abdomen vermilion, becoming narrower from the second segment. 

 Antennce and legs black; thorax rarely entirely black, usually the mesonotum in 

 front of the scutellum and the edge of the pronotum are red. Wings blackish, 

 the stigma and nervures at the apex usually more or less fuscous. (Species 50-54.) 



The area on the second segment being broader and not prolonged into a keel, but 



