370 JOURNAL OF THE WASHINGTON ACADEMY OF SCIENCES VOL. 13, No. 16 
tubercle and the posterior scutellar ridge piceous; (the scutum has two oval 
brownish spots, but inasmuch as these are asymmetrical it is probable that 
they are due to discoloration); apical part of the abomen ferrugineous; 
wings hyaline, iridescent, with a slight yellowish tinge; venation fulvous, 
except black stigma. 
Type-locality—Kartabo, Bartica District, British Columbia. 
Described from a single female collected by P. G. Howes, 1922, and given 
his number 16622. -This specimen is collected with its nest. The nest in 
general outline agrees very well with Ducke’s figure of the nest of MW. theridii2 
Type.—Cat No. 26480 U.S.N.M. 
Microstigmus brunniventris, new species. 
The dark abdomen readily distinguishes this species from the other known 
forms. 
Female.—Length 2.25 mm. Clypeus convex, the anterior margin with a 
broad, gentle emargination; interocular quadrangle broader than high; the 
lower part of frons finely granular, the rest of the head polished; flagellum 
only slightly thickening apically, short, first joint slightly shorter than the 
second; ocelli in an equilateral triangle; dorsal surface of pronotum polished, 
the anterior margin with a sharp carina; scutum rather coarsely granular and 
in some lights with a tendency to become feebly rugose; scutellum pyramidal 
but, when seen from the top, with lozenge-shaped area; posterior margin with 
a low ridge; dorsal surface of the propodeum U-shaped with two median 
longitudinal ridges on a feebly reticulate surface; posterior face of the propo- 
deum coarsely reticulate, the reticulations in three series so that at some 
angles there appear to be three transverse ridges; mesepisternum reticulate ; 
sides of the propodeum granular and with large, poorly defined reticulations; 
petiole longer than the hind coxa, with two carinae which become approximate 
medianly; abdomen highly polished; stigma triangular, its greatest width 
distinctly greater than the first abscissa of the radius. Ferrugineous; apices 
of the antennae, dorsal aspect of the propodeum piceous; abdomen, including 
petiole, very dark brown; legs testaceous; wings hyaline, iridescent; venation 
testaceous, except a dark brown stigma. 
Type-locality.—San Bernardino, Paraguay. 
Described from a single female collected May 19th by K. Fiebrig. 
Type.—Cat No. 26481 U.S. N. M. 
Stigmus fulvicornis, new species. 
This species seems to be closest to S. conestogorum Rohwer, but it is smaller, 
the intermediate legs are pale, and the sides of the pronotum are without a 
dentation. 
Female.—Length 3mm. Head, when seen from above, subquadrate, though 
slightly narrowing posteriorly; anterior margin of the clypeus bilobed; front 
very finely granular, rest of the head smooth and polished; antenna simple, 
the third joint subequal with the fourth; dorsal surface of the pronotum rather 
coarsely rugoso-granular, the transverse carina rather feeble and subdentate 
laterally; sides of the pronotum not dentate; mesoscutum polished, under 
high magnification feebly reticulate anteriorly and with the usual impressed 
2Ann. Soc. Ent. France, 76:29. 1907. 
