105 
of ocellar basin very minutely but sharply raised, becoming obsolete 
posteriorly; frontal crest acutely elevated, angulated, and extending 
nearly to orbits; antennal fovea broad, extending laterally over bases of 
antennae; antennae long, slender, third joint longer than fourth; inter- 
costal cross nerve nearly twice its length anterior to basal nerve, 
slightly inclined; second recurrent interstitial, or nearly so, with second 
transverse cubital; venation otherwise normal; stigma broad, regu- 
larly rounded beneath; sheath broad, straight on upper margin, 
obliquely truncate at apex, bordering hairs minute, scattering; cerci 
long, scarcely tapering; inner tooth of claw small, remote from apex. 
Color black, shining; apex of clypeus and other mouth parts, outer 
third of pronotum, tegulae, anterior pairs of legs entirely, posterior pair 
except extreme bases of coxa' and apices of femora and of tibiae and all 
of tarsi, venter of abdomen except overlapping sides of last dorsal seg- 
ment and sheath, very narrow lateral margin of abdomen dorsally, and 
more or less of apex of all segments yellowish white; femora, partic- 
ularly hind pairs, more or less inclined to reddish: stigma and veins, 
except base of costa and slightly at apex, brown. 
Male. — Length 5 to 5.5 mm.; structurally for the most part as in 
female; antenna' very broad or strongly compressed, tapering; j)roci- 
dentia rounded at apex, not constricted basally, strongly keeled. Color 
black; tips of clypeus, mouth parts, angles of pronotum, teguhc, venter 
of abdomen, and legs except extreme bases of coxa' and apices of pos- 
terior tibia' and tarsi of same, yellowish ferruginous; venter of abdomen 
infuscated laterally, and sometimes more or less entirely. 
Seven females and three males. Canada, New Jersey, New Hamp- 
shire, Pennsylvania, and Illinois (Coll. Am. Ent. Soc), and Colorado 
(Coll. TT. S. Nat. Mus.). 
22. Pachynematus snbalbatus Norton. 
1864. Nematua aubalbatua Norton. Proc. Ent. Soc. rhila., in, p. 7. 
1867. Nematua subalbatus Norton. Trans. Am. Ent. Soc, i, p. 199. (Cat., etc., 
p. 61.) 
1878. Nematua subalbatus Trovanchcr. Nat. Can., x, p. 54. 
1883. Nematus subalbatus Provancker. Faun. Ent. Can. Hym., p. 181. 
Female. — Length 8 mm.; rather elongate; head densely and closely 
punctured or rugose; clypeus distinctly but not deeply emarginate, 
lobes rounded; frontal crest very strongly developed, very slightly 
broken at center, not reaching orbits; sides of ocellar basin distinct, 
but not strongly elevated; antennal fovea distinct, broadening poste- 
riorly into a suture beneath frontal crest; antennae longer than head 
and thorax, moderately robust, tapering, third joint longest; venation 
normal, except that second recurrent is interstitial, or nearly so, with 
second transverse cubital; stigma broad, scarcely tapering, until near 
apex; sheath rather broad, rounded, truncate at apex, straight on 
upper margiu; cerci rather stout, tapering; inner tooth of claw minute, 
