MONOGRAPH OF THE NORTH AMERICAN PROCTOTRYPIDyE. 37 



as thick, the last joint twice as long- as tlie peuiiltimate. Thorax 

 anteriorly narrowed, the collar brownish, the niesonotimi with 4 grooves, 

 the middle fnrrows more or less indistinct and abbreviated posteriorly, 

 the scntellnm with a transverse furrow at base, the metathorax twice 

 as long- as wide, rngulose, with a median carina. AYings subhyahne, 

 the stigma and nervures pale brownish-yellow, the transverse median 

 nervnre evected. Legs brownish-yellow, the posterior coxte somewhat 

 dusky. Abdomen oval, piceous-black, the apical edges of the segments 

 testaceous. 



Habitat. — Spokane Falls, Wash. 



Type $ in Coll. Ashmead. 



The largest species in the genus known to me, and readily dis- 

 tinguished by the evected transverse median nervnre. 



Isobrachium niyimecophiluni s]). iiov. 



(PI. II. Figs. B, <?; 4, 9.) 



5 . — Length 3'""'. Head twice as long as wide, black or i)iceous, 

 shining, punctate, and sparsely covered with a dusky pubescence. 

 Eyes and ocelli entirely wanting. Mandibles rufous, with 3 teeth. 

 Antenna) short, 13-jointed, rufous, the scape nearly one-half as long as 

 the tlagellum; pedicel small, rounded; the flagellar joints, except the 

 last, all transverse, the last oblong, more than twice as long as the 

 preceding. Thorax brownish-piceous, highly polished, with a few 

 scattered punctures; the i)rothorax is greatly elongate, 2i times as 

 long as wide, with nearly parallel sides rounded off anteriorly, the 

 anterior dej)ression of the collar pale rufous, finely transversely acicu- 

 late; prosternum black; mesonotum separated from the pronotum by 

 a distinct furrow; the mesothorax is separated from the metathorax by 

 a strong constriction, trilobed but without a scutellum; the metathorax 

 is scarcely larger than the middle mesothoracic lobe. Legs pale brown- 

 ish-yellow, stout, the middle tibia) strongly spinous; all tarsi longer 

 than their tibiae. Abdomen oblong oval, brownish piceous, much 

 shorter than the thorax, smooth, impnnctured, vsparsely pilose. 



$ . — Le^igth 3 to 3.5""". Black, punctate; head oblong, with a thim- 

 ble-like punctuation, mandibles rufous, antenuii; and legs pale ])rown- 

 ish-yellow, collar pale anteriorly; abdomen x^iceous, paler at sutures. 



Antennae 13-jointed, extending to base of scutellum, the flagellar 

 joints not quite twice as long as thick. Thorax with 4 grooved lines, 

 the middle pair parallel, abbreviated posteriorly; those on the shoulder 

 abbreviated anteriorly. Metathorax long, minutely shagreened with 

 a central longitudinal carina. Wings hyaline, the stigma and sub- 

 costal nervnre pale brownish, the other nervures subhyaline; the radius 

 is very long, almost reaching to the apex of the wing, the transverse 

 median nervnre, oblique, interstitial with the basal. 



Habitat. — Pennsylvania, District of Columbia, Montana, and Ari- 

 zona. 



Types in Coll. Ashmead. 



