1865.] 25 



rather large white spot on each side behind. Wings hyaline, beautifully 

 iridescent; nervures and stigma fuscous. Legs pale honey-yellow, the 

 four anterior coxae white. Abdomen elongate, slender, black or brown- 

 black, base of the first segment yellowish, and the apical margins of all 

 the segments white. Length 2| lines; expanse of wings 4t\ lines. 

 Collection. — Ent. Soc. Philad. One specimen. 



Genus ISCHNOCERUS. Grav. 

 Ischnocerus abdominalis. n. sp. 



Black: orbits, spot on clypeus, annulus on antennae, collar, tegulse and seu- 

 tellum, white: abdomen and legs rufous: wings hyaline. 



Female. — Black; the orbits and a spot on the clypeus, white; an- 

 tennae two-thirds the length of the body, black, the 7th to 11th joints 

 white. Thorax with two well impressed dorsal lines; collar, two short 

 lines on the disk of the mesothorax, tegulae, a sutural line before and a 

 short line beneath the wings, white ; scutellum polished, white ; meta- 

 thorax finely sculptured, the elevated lines scarcely defined. Wings 

 hyaline, faintly clouded at the apex ; nervures and stigma blackish ; 

 areolet wanting, or subobsoletely incomplete, the 2nd recurrent uervure 

 very straight. Legs, with their coxae, rufous ; the posterior tibiae and 

 tarsi blackish ; tibial spurs whitish. Abdomen robust, elongate-sub- 

 ovate, convex, petiolated, arcuated, shining, rufous; first segment square 

 towards the tip ; base of the second and third segments obfuscated ; 

 ovipositor rufous, rather more than half the leugth of the abdomen. 

 Length 5 lines ; expanse of wings 8 lines. 



Collection. — Dr. J. Grundlach. One specimen. 



Genus MESOSTENUS, Grav. 

 Mesostenus robustus, n. sp. 



Black; antennae with a white annulus; face, orbits, collar, spot on disk of 

 mesothorax, tegulae, line before and beneath the wings, most of pleura, scutel- 

 lum, 4 lines on metathorax, legs and apical margins of abdominal segments, 

 pale yellowish; wings hyaline; mesothorax with two stout, subacute spines. 



Female. — Very robust, opaque ; head black, face, orbits, cheeks, 

 and palpi, dirty whitish ; an obtuse tubercle on the middle of the face, 

 the clypeus, labrum and a spot at base of mandibles, more whitish ; 

 lateral sutures of the clypeus and the apical half of the mandibles, 

 black ; antennae as long as the body, slightly thickened near the tip, 

 black, with a broad white annulus beyond the middle, basal joint be- 

 neath with a white line. Thorax black ; mesothorax punctured, the 

 dorsal lines deeply impressed, middle lobe with a large yellowish spot 

 at tip, the lateral margins also narrowly yellowish for half their length 

 towards the front, lateral pieces margined laterally with yellowish ; the 

 carinae leading to the scutellum also yellowish ; the collar, upper mar- 



