57 
defined and strongly raised walls; frontal crest prominent, sharp, 
unbroken; fovea distinctly defined, oval; second, third, and fourth 
joints of antenne subequal; venation normal, except that the third 
cubital celi is quadrate; sheath short, obtusely pointed, quite densely 
clothed with hairs; cerci slender, slightly tapering; claws deeply cleft, 
rays subequal. Color black; center of basal segment of abdomen 
above and all of three following segments and more or less of the base 
of the succeeding segment reddish yellow; tip of clypeus and mouth 
parts, anterior legs for the most part, coxe except bases, trochanters, 
bases of femora, and basal half of tibie of hind legs pallid; angles of 
pronotum and the tegule pallid, infuscated; femora of fore and mid- 
dle legs rather strongly infuseated; stigma and veins dark brown; 
wings nearly hyaline; spot in second cubital cell prominent. 
2edescribed from Harrington’s type specimen, (Coll. Harrington.) 
18. Pteronus erythrogaster Norton. 
1864. Nematus erythrogaster Norton. Proc. Ent. Soc. Phila., 11, p. 8. 
1867. Nematus erythrogaster Norton. Trans. Am. Ent. Soc., 1, p. 205. (Cat., ete., 
p. 67.) 
> 1886. Nematus erythrogaster Provancher. Add. faun. Can. Hym., p. 23. 
Female.—Length 7.5 mm.; moderately robust, shining; head and tho- 
rax finely punctured; clypeus shallowly and broadly emarginate, lobes 
triangular, rather pointed; frontal crest and sides of pentagonal area 
strongly raised, former unbroken; antennal fovea cireular, deeply exca- 
vated; antenne moderate, somewhat longer than head and thorax; 
intercostal very near basal vein; second cubital cell more than two- 
thirds as wide at base as at apex; upper cell of hind wings exceeding 
lower; stigma broad, ovate, not attenuated; sheath rather robust, rugose 
and with numerous hairs. Color of head and thorax for the most part, 
basal plates, first segment of abdomen dorsally, sheath, cerci, extreme 
bases of hind cox, tips of hind femora, apical two-thirds of hind tibie, 
and all of hind tarsi black; extreme tips of clypeus and the labrum, 
palpi, outer angles pronotum, tegule, abdomen, and legs, except as 
noted, rufous; basal third of hind tibiz whitish; veins and stigma in 
general brown; costa and some of posterior veins light. 
Two females. Maryland (Coll. Am. Ent. Soe.), and Ithaca, N. Y., 
N. Banks, collector (Coll. U. S. Nat. Mus.). 
19. Pteronus corylus Cresson. 
1880. Nematus corylus Cresson. Trans. Am. Ent. Soc., Vit, p. 8. 
1895. Nematus corylus Dyar. Trans. Am. Ent. Soc., xxu, p. 306. 
Female.—Length 6 to 7 mm.; head and thorax rather coarsely punc- 
tured, somewhat shining; clypeus very shallowly emarginate, lobes 
very short and broadly rounded; frontal crest and sides of ocellar basin 
distinctly elevated, former unbroken, or rarely indistinctly so; antennal 
fovea broad and shallow, antenne long, tapering, third joint longer 
than fourth; venation normal, second transverse cubital nearly as long 
