ART. 15. REVISION OF ICHNEUMON-FLIES MUESEBECK. 37 



19. MICROGASTER SWAMMERDAMIAE, new gpecieg. 



The distinct punctation of the entire mesoscutum and sciitenmn 

 and the short ovipositor will readily distinguish this species from its 

 closest allies, carinata^ canadensis, and congregatiformis. 



Female. — Length, 2.8 mm. Face a little broader than long, with 

 closely placed distinct punctures, and with an indistinct shining me- 

 dian tubercle below the antennal fossae; antennae distinctly longer 

 than the body, mesoscutum entirely distinctly punctate, shining; 

 scutellum large, nearly flat, more feebly, but distinctly, punctate; 

 mesopleurae mostly smooth and polished, only weakly punctate an- 

 teriorly and below; propodeum rugulose, with a prominent median 

 longitudinal carina; stigma broad, shorter than the metacarpus; 

 radius arising slightly beyond middle of stigma, somewhat directed 

 backward, only a little longer than the first intercubitus ; posterior 

 coxae at least half as long as thorax, mostly polished, with a flat- 

 tened punctate area on the outer upper edge; inner spur of middle 

 tibiae a little longer than middle metatarsus ; inner spur of posterior 

 tibiae two-thirds as long as posterior metatarsus; abdomen narrower 

 than, and about as long as, thorax, at least two and one-half times 

 as long as broad; first tergite broadening posteriorly, indistinctly 

 longer than broad at apex, finely rugulose; second tergite transverse, 

 slightly more than twice as broad as long, and distinctly longer 

 than the third, very finely rugulose, the suture between it and the 

 third very minutely crenulate and straight; third tergite practically 

 entirely smooth and shining, with only a faint suggestion of rough- 

 ening at the extreme base medially, remainder of dorsum of abdomen 

 smooth and shining; ovipositor sheaths slender, projecting only 

 one-fourth the length of the abdomen. Black; labrum and apex 

 of mandibles reddish ; labium and palpi pale yellow ; antennae wholly 

 brownish black; tegulae black; wings hyaline, with the apical half 

 weakly fuliginous; all coxae black; remainder of the legs bright yel- 

 low, except the extreme apex of posterior femora and tibiae and the 

 posterior tarsi, which are infuscated. Abdomen black above; the 

 narrow membranous margins along the first and second tergites and 

 most of the venter, pale yellow ; sometimes the third tergite is pale 

 at extreme sides. 



Male. — Like the female in all essential characters. 



Cocoons. — 4.5 mm. long, cylindrical, white, thin, with an indistinct 

 semitransparent band near the middle. 



Tyjpe locality. — East River, Connecticut. 



Type.— C2ii. No. 23993, U.S.N.M. 



Host. — Swammerdamia. castaneae Busck. 



Described from four female and eight male specimens reared by 

 C. R. Ely at East River, Connecticut, August 4, 1917. There is in 



