296 E. T. CRESSON. 



sharply defined, the central area small, subrotund; wings yellowish-hyaline, 

 iiervures and stigma testaceous; legs bright honey-yellow, approaching orange, 

 the four anterior coxae whitish, the posterior pair black, more or less yellow at 

 tips; tips of posterior tibire, and sometimes the apex of their tarsi, dusky; ab- 

 domen long and narrow, opaque, except at tip which is smoother and slightly 

 shining: basal segment slender and but slightly dilated at tip, which is bicari- 

 nate and finely striated longitudinally. Length 7i lines. 

 Eab. — Canada, (Saunders) ; Maine, (Harris' Collection). Two % specimens. 



I. puerilis. — %. Very slender, black, shining ; face, clypeus, mandibles and 

 palpi, white; a dusky spot beneath antennte and a larger one on middle of ely- 

 ])eus ; antennae very long, slender, filiform, brown above, fulvous beneath, the 

 basal joint white beneath ; tegulse and a spot on scutellum, fulvous; the post- 

 scutellum has two large, deep fovese at base; metathorax shining, the elevated 

 lines well defined, the central area moderate, quadrate; wings hyaline, irides- 

 cent, nervures and stigma brown, areolet triangular; legs, including all the 

 coxje, bright honey-yellow, tips of posterior femora, their tibios and tarsi black- 

 ish ; abdomen slender, the apical half polished. Length 5 lines. 



Hah. — Canada, f Billings). One % specimen. This is a very slender species, 

 with very long, filiform antennae. It may not belong to this genus. 



I. infidelis. — %. Black; face, orbits, spot on each side of cylpeus, and palpi, 

 whitish; antennae long, slender, subserrate, entirely black; tegulae, broad sutu- 

 ral line before, and a short line beneath each anterior wing, most of scutellum, 

 post-scutelium, and two spots on each side of the pleura, the anterior one the 

 larger and transverse, all white; scutellum slightly convex ; metathorax con- 

 fluently punctured, the elevated lines sharply defined, the central area large, 

 lunate, and on each extreme side there is a very obscure pale mark; tegulre 

 dull whitish; wings hyaline, nervures and stigma black; legs black, the four 

 anterior coxse more or less whitish beneath, the posterior with a white spot be- 

 hind ; tips of the four anterior femora and within, their tibiae and most of tarsi, 

 extreme tips of posterior femora, the exterior edge of their tibiae and most of 

 their tarsi, whitisli ; abdomen robust, opaque at base, shining at tip; apex of 

 first segment white, apical margin of second segment stained with dull testa- 

 ceous. Length 7 lines. 



Hab. — Connecticut, (Coll. Mr. Xorton). One % specimen. 



I. improvisus. — %. Black, subopaque ; face and clypeus white, both with a 

 broad black stripe down the middle; antennae long, slender, black, with a broad 

 white annulus a little before the middle, the basal joint beneath is spotted with 

 white; spot on tegulaj, another in front, a short line beneath, and the scutel- 

 lum, also white; central area of metathorax subquadrate, shining; wings sub- 

 hyaline; legs black, tijjs of anterior femora, their tibite and tarsi, basal half of 

 intermediate tibiae and of their tarsi, and a narrow band near the base of pos- 

 terior tibiae, white; abdomen elongate, narrow, opaque shining at tip, apical 

 margin of sixth and a large spot on the seventh segment, white. Length 6i 

 lines. 



JIab. — New Jersey, (Coll. Mr. E. Norton). One % specimen. 



I. ssevus. — 9 • Robust, deep black, shining, closely and distinctly punctured 

 antennae with a broad yellowish annulus ; head and thorax immaculate, except 

 the posterior jnargin of the scutellum, which is obscurely palish; metatho- 

 rax shining, sparsely punctured, central area large, rounded in front and emar- 



