66 
and distinctly excavated; lateral walls rounded; frontal crest strongly 
developed, divided by narrow depressed line at middle; antenna! fovea 
deep; antennae slender, strongly tapering, joints 4 and 5 subequal; 
venation normal; sheath narrow, tapering to rounded tip; claws deeply 
and evenly notched. Color of antennae, large spot including ocelli and 
extending over vertex, dorsum of thorax, and abdomen black; posterior 
tibiae darker at tips, with tarsi brown; sheath brown; veins brown, 
stigma scarcely paler; face, orbits, pronotum, teguhe, entire venter, 
with lateral edges of dorsum of abdomen, pallid or resinous. 
Male. — Length 5 mm.; slender; antenna* not much stouter than in 
female; procidentia short, narrow, projecting about its own width. 
Color as in female, except that the antenna' are fulvous beneath and 
the pectus is strongly infuscated. 
Eleven females and live males (Coll. Cornell Univ.), labeled "Lot S5, 
sub. \)(ti," dated May to July, 1890. 
33. Pteronus trilineatus Norton. 
1867. Sennit us trilineatus Norton. Trans. Am. Ent. Soc, i. p. 215. (Cat., etc., 
p. 77.) 
L872. Nematus trilineatus Norton. Trans. Am. Ent. Soc, iv, p. 7!». 
1877. Nematus trilineatus Gloyer. Sept. U. 8. Dept. Auric, p. 92. 
1880. Nematus eimilaris Norton. Kept, Ent. U. B. Dept. Agric 1879, p. 224, I'l 
III, fig- 1. 
1881. Nematus trilineatus Thomas. lOtli Kept. Ent. 111., 18S0 ; p. 68. 
,1885, Nematus robinia Forbes. 11th Bept. State Ent. 111., 1881, p. 116, PI. 12, 
fig. 5. 
1886. Nematus similaris Harrington. Can. Ent., win, p. 39. 
1886. Nematus similaris Provancher. Add. Faun. Can. Hym.,p. 24. 
L890. Nematus eimilaris Packard. Kept. U. S. Ent Comm., v, p. 369, fig. L36, 
1890. Nematus robinia Packard. Kept. U. S. Ent. Comm., v, p. 370. 
L895. Nematus Hmilaris Dyar. 'Trans. Am. Ent. Soc, xxn, p. 301 (larva). 
Female. — Length <i.o to 7 mm.; moderately robust, shining; clypeus 
bmadly, circularly, but deeply emarginate, lobes large, triangular; 
frontal crest and sides of ocellar basin distinctly denned, former un- 
broken, curving anteriorly; antenual fovea triangular, sharply defined; 
antennae long, slender, tapering, third and fourth joints equal or lat- 
ter longest; venation normal; intercostal vein slightly inclined; third 
cubital nearly three times as long as wide at base; stigma moderately 
robust, widest at center; sheath narrow, smooth, tapering on both 
edges to rounded tip; cerci slender, not tapering; rays of claws nearly 
equal. Color reddish yellow; antennae, spot on head surrounding 
ocelli and extending over occiput, anterior and lateral lobes of meso- 
uotuin, small spot beneath anterior wings, metanotum (except meta- 
scutellum, sutures, and lateral margin), abdomen (except lateral margin 
of segments and last segment), apical half of sheath, and posterior 
tibia' and tarsi brownish black; antenme fulvous beneath toward tips; 
tips of anterior tarsi dusky; veins, including costa to base and stigma, 
brown, latter darker basally. 
Twelve females from Canada, Massachusetts, New York, Kansas, 
