1910] Girault and Sanders — Chalcidoid Parasites 111 
furrows distinct, complete; axilla widely separated, extending mesad to the 
parapsidal furrows; scutellum normal, rounded; metathorax moderate in 
length, shorter than the scutellum, declivous, the pro- and mesonotum flat, 
the metanotum punctate, with complete lateral carine, without spiracular 
sulci and with no true median carina but with a distinct, subacute rotundity 
at its base medially; its spiracle moderately large, subreniform; no meta- 
thoracic neck. Abdomen with a moderate petiole, variable in shape, usually 
ovate and depressed, concave dorsad, flatly convex ventrad, with a slight 
ridge along the venter at the meson; rarely compressed and conic-ovate, 
flat dorsad, very convex ventrad but not long; second and third abdominal 
segments large, united forming about half the length of the abdomen (ex- 
cluding petiole), the fourth and fifth segments subequal, much smaller; 
abdomen about equal in length to the thorax. 
Wings normal, hyaline, the short and broad marginal vein subequal to 
the clavate stigmal vein and a fourth shorter than the narrow post-margi- 
nal vein; hind wings uniformly ciliate discally. Knob of stigmal vein 
small. 
Tarsi 5-jointed, all tibial spurs single. Mandibles 3 and 4-dentate (Fig. 
2). Maxillary palpi 4-jointed, the distal joint largest, labial palpi 3-jointed, 
the middle joint smallest, the others subequal. 
Male. The same, but the antenne are cylindrical and inserted nearer to 
the middle of the face, the genal sulcus present, the abdomen obconic and 
aepressed and more or less truncate at the caudal end. 
The genus cannot be confused with any other of the tribe Pachy- 
neurini, excepting Pachycrepis Forster, the complete, distinct 
mesothoracic furrows distinguishing it. From Pachycrepis it dif- 
fers in the smaller stigmal knob and the abdominal characters 
brought out in the quoted portion of Ashmead’s table given 
previously. 
No locality for the type species has been recorded in the litera- 
ture, but the single type specimen now in the United States Na- 
tional Museum formerly bore the number 602 of C. F. Baker, 
Agricultural College, Michigan. We have found it only at Cham- 
paign, Illinois. 
Our knowledge concerning the host relations of the genus is too 
scanty for positive statement. As shown on a later page, the single 
species was reared always in connection with Musca domestica, and 
in four of the six rearing records it was definitely connected with 
that host of which it appears to be a primary parasite. Muscidi- 
furax Girault and Sanders MS. and Spalangia Latreille are com- 
mon primary parasites of the house fly, and in one instance each was 
